SuzukiSavage.com - Print Page

SuzukiSavage.com
/cgi-bin/YaBB.pl
General Category >> The Cafe >> Is it possible to make a cheap DIY Air Fuel Meter?
/cgi-bin/YaBB.pl?num=1334080904

Message started by spacepirates on 04/10/12 at 11:01:44

Title: Is it possible to make a cheap DIY Air Fuel Meter?
Post by spacepirates on 04/10/12 at 11:01:44

... Using an O2 sensor off a car?

Here is my train of thought:
Jetting is an art, and is a long process to do. Often times you cover up a lean spot with a rich spot or vice versa and it is more qualitative than quantitative when you are trying to measure how well it is jetted.
What we are shooting for here, is a "perfect" air/fuel mixture, roughly 14.7:1 (depending on the gas used).
In the push for more efficient engines, the O2 sensor was developed to measure and adjust the air/fuel mixture (technically, it just measures left over oxygen...) in EFI cars. BUT, it has to give some sort of output or recognizable control signal to do so. This is done via a voltage, between .2v and .8v (lower being leaner, .45v ideal mixture. source: http://en.wikipedia.org/wiki/Oxygen_sensor#Zirconia_sensor)
There exist AFR (air/fuel ratio) meters already, but those are hundreds of dollars and I'm one cheap SOB.

I've stumbled across this site:
http://www.scirocco.org/tech/misc/afgauge/af.html

I want to take it one step easier/cheaper:
In your opinion(s), given that someone out there probably knows better than I do, would it be possible/accurate/feasible/"worth it" to take a cheap O2 sensor ($25?) and wire it to a multimeter such that I can read the voltage to get a better idea of how my bike is jetted?

I would have to mount the O2 sensor somehow/somewhere and think about how accurate this setup would be.

Thoughts? Would it be too much effort to mount an O2 sensor? Would this not work for some reason I didn't think of?

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 04/10/12 at 11:19:20

Well,, pardon me for saying so,, but I think youre some kinda Smart! I mean,, the O2 sensors in the exhaust of a car send a signal, decoded by the computer & used to adjust injector firing, right? I dont see why reading your exhaust cant be used to tell you where you are lean/rich in your rpm ranges,, & under heavy/light loads..
Getting a sensor installed,,, hmmm,,, How about getting a short sleeve cut to put between the header & muffler, so it doesnt have to be permanent? Put it in, make the runs, study the meter, see what the carb needs, adjust ( or not) & pull it off & put it in the toolbox..?
The header is double walled outfit, so, installing there requires cutting thru both,, gonna be messy..
Or, maybe poke a hole in the muffler inlet & have the threaded pipe welded in there? That would keep the exhaust the same length & keep the mounts lining up..
You could take it off & have it done on the lower, inside area & run the wires up the canister carrier & up the frame, under the tank & to the handlebars..

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by Boule’tard on 04/10/12 at 12:14:47

Just take a voltage reading across the O2 sensor connectors while it is hooked up to a good-running car. Then tune your bike to try to get it to match that voltage at most loads/RPM/throttle positions. Simple!! ;D

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by Boule’tard on 04/10/12 at 12:37:53

On a more helpful note, this thread shows an install/use of a not-too-expensive AFR meter. Of course you'd still have to find a good place to mount it.

http://www.thumpertalk.com/topic/876726-no-cost-dr650-jetting-upgrade-%E2%80%93-phase-i-backward-tuning/page__hl__o2%20sensor

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/10/12 at 12:42:12

To be fair, I'm really only trying to be cheap where other people have gone the safe route. I have a bad habit of over-simplifying things and getting burned because of it.

Inserting a short sleeve sounds like the most re-usable method, but that changes muffler length and requires that you "compromise" your header/muffler seal/connection.

I'd like to avoid involving the header. Smaller, more curved, more walls, harder to replace (and by that i mean it is more expensive and less common than mufflers).

I don't know enough about O2 sensors to reasonably decide where it could be placed. I mean, if the bike isn't moving, couldn't you just shove it up the muffler ;D

Maybe if you drilled and tapped a hole in the muffler that you could either permanently leave the O2 sensor in, or otherwise plug up afterwards.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by jimbobbert on 04/10/12 at 12:46:29

With the limitations already mentioned about the stock header construction, it would be much more feasible to install near/on the muffler. the problem here is exhaust gas velocity, as the gasses enter the muffler they slow down substantially due to the larger diameter. With installing the sensor at the start of the muffler, you would need to do it in such a way as to subject the probe to a constant, flowing stream of exhaust gasses, in order to avoid false readings from stagnant "pockets" of air. In addition, one would need to avoid impeding the actual flow of air with a blockage in the duct, in which case it is highly dependent on the diameter and length of the sensor probe as well as placement.

another little bump in the road here is that once you get your engine tuned correctly at one Temperature/Air density/humidity level/engine load, your bike may require a different mixture at other atmospheric levels. The good thing is, however, most everyone leaves the jetting alone once it is "close" until it interferes with the ridability of the motorcycle, and only then do we change it. so, with a few pulls on a dyno, we can get the bike running just about perfect for full-load runs at a specific temp/air density and be ahead of the game. At that point, do some "normal" pulls to replicate street riding and ensure the mixtures stay in a safe zone, and rideability is preserved.

Data logging software would be extremely useful here because it's hard enough to whack the throttle open from off-idle to redline in 4th gear and be safe about it, (on the street) than to add in keeping an eye on a multimeter readout and taking notes :o Also a much higher level of accuracy is gained, since many digital multimeters take samples at fewer intervals than what is required to obtain high-quality readings. Simply stated, your bike may go from rich to lean to rich again quicker than the meter can react, and you won't notice because it just showed rich for the entire time. Several 'pulls' must be done, in a high enough gear, to ensure accurate readings are obtained over the entire RPM range, And this is all for a strictly Wide-open throttle condition- intake velocity is different at varying RPMs with different throttle openings, such as 1/2 throttle at 5000 RPM vs. full throttle at 1200 RPM. higher velocities mean more pressure differential, which all comes out to more fuel being drawn into the intake. This is why FI is so dang nice... a computer does all these calculations and adjusts for them, based on throttle position, intake vacuum, RPM, ambient temperature, intake airflow velocity, and sometimes even which gear you are in, in addition to adjusting the timing of the spark to go with the different fuel maps.

Rob

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/10/12 at 12:48:36

49445E474E5F4A594F2B0 wrote:

According to my research (I love saying that), the ideal voltage for a Zirconia-style sensor is .45v. That wikipedia page I linked to earlier also has readings for other style O2 sensors.

that thumpertalk thread is good stuff, but I think the AFR sensor he used was still fairly pricey. and by that i mean more than $20. It does show me how an O2 sensor looks in relation to a header though, much more intrusive than I expected (as in, the sensor sticks out into the header a lot).

I'll have to chew on this a bit further. The electronics don't bother me, it is mounting the O2 sensor that is getting me. I don't have a machine shop at my back, nor do i have a welder (or even a tap and dye set!) so we'll see. either way, food for thought for anyone more mechanically ambitious for the time being.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by jimbobbert on 04/10/12 at 12:54:15

sorry to have gone off on a tangent there. I guess what i was meaning to get across is that it should be possible to get a more accurate idea of what your bike needs with a slaved in 02 sensor, than it would be without one. However, you must already be pretty familiar with how to jet a carburetor, to fully appreciate and ultimately be able to use the readings you obtain from the sensor.

My Savage will have a bung installed in the exhaust i will be making for it, just for this purpose. I bet a dial-a-jet would be very useful here for on-the-fly adjustments, hmmm need to order one now for my VM36...

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 04/10/12 at 13:30:37

Id think a drill to poke a hole & a short coupling to have welded in wouldnt be that big of a deal,, you mite even be able to find a machine shop to do it for cheap.. I had one drill a hole for me in some pretty tuff steel, ( I had no idea how hard it was till he stated drilling),, I would have spent more buying the bit & my pukey drill press wouldnt have done it, not in a year. I worked in a shop & we had a welder,, but maybe thats not so common,
Call around to a few machine shops, & welding shops,, a welder with a drill press shouldnt be that strange.. ya never know,, sometimes those guys just treat people nice. I sectioned my header out when I took the interior pipe out. I did it carefully & made it so putting it back would be easy. I found a guy who tig welded it back,, he let me walk,, free,, of course,, I watched & was aware of what he would need & was there with it & put everything back exactly where I got it,, & he saw I respected him & his shop,, & that never hurts,,

A pipe coupling, shortened, on a cut off grinder, otta work fine,, just get a nipple to screw in one end so you can steady it in the cutoff tool.
No need for a tap..drill & weld it in,

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by verslagen1 on 04/10/12 at 13:57:36

I've looked at one of the instructions for a/f meters and they menstion stuff like pre heating so I think there's more to it then hooking a vom to it and getting a reading.

As to placement... has to be far enough from the end to prevent blow back from the outside screwing up the readings. The temporary ones have a probe that stuck up past the muffler and have an exhaust extention just as long, all coiled up.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/10/12 at 15:21:25

Just did a quick look on flea-bay for a spare header, doesn't look like there are any. bummer, as it does seem like the header is the place to put the O2 sensor.

spit-balling the price for reading it with a voltmeter:
header - free
bung/O2 mount - $10
O2 sensor - $25
drilling/welding - free if DIY or ?
AFR gauge electronics - $10 (optional)

So for $50 and a beer (to pay your friend with or to drink yourself!) you've got a start (if anyone in the pittsburgh area would like a beer, i've got a header if you've got a welder *hint hint nudge nudge*). and assuming you can leave the O2 sensor and volt meter attached (safely!) while riding I'm sure you can get a better idea of your jetting than just "feels lean" or "feels about right."

My header is wrapped (oh no! horror of all horrors!) but I think this project would be worth unwrapping it. plus then we get to see if wrap over a year (roughly) and some nasty wet weather is really horrible for your pipe!

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by Boule’tard on 04/10/12 at 15:56:22

Well on the bright side, if you don't like the looks of the sensor/bung setup, you can always grind it off more or less flush, seal it up and once you re-mummify it, you won't see any difference.

I am surprised you can find a sensor for 25 bucks. I thought they were around $100 just for the plug, never mind any electronics.

Hopefully you can bribe someone with a welder over there, install it and post some pics. Of course you realize, if you are successful, everyone and their dog is going to want you to try their particular filter/jetting/muffler setup.. hmmm maybe you can charge for that and recoup some of the cost! :D

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/10/12 at 18:53:41

606D776E6776637066020 wrote:

Yeah, I won't see a difference, but I'd still *know*.

Bung: http://www.amazon.com/Holley-534-49-Weld-In-Oxygen-Sensor/dp/B00029JK32
Sensor: http://www.amazon.com/Bosch-15717-Oxygen-Sensor-Fitment/dp/B000BZI4JS/ref=sr_1_12?s=automotive&ie=UTF8&qid=1334108683&sr=1-12

Those aren't shopping around, I just immediately go to Amazon and then search around and price check after. I don't know what they'd be at autozone or elsewhere, and there are plenty in the $90+ range on amazon too. Not sure why there is a difference, but we really aren't going for dead-on accuracy or 100k+ mile lifetime on these things, so cheap should work.

As for matching people's setups, sadly, I busted my stock carb by punching the air/fuel mixture screw into the carb and stripping the threads and head, so now I'm on a VM38. BUT! (and there is always a "but") I could always sell kits! but that isn't very lucrative or very fair. oh well. I'll recoup the cost with the value of lots of sound sleep knowing my bike is jetted as well as a carb in varying elevations and weather conditions can be (read: just moderately ok).

Like I said before, give me a few more days to mull this over and talk with some more automotively educated fellows about the feasibility and maybe in a week or two we can see if I've just been wasting everyone's time here or not.

EDIT: to clarify, the bung costs $11 shipped (with amazon Prime) (model: Holley 534-49 Weld-In Oxygen Sensor Bung) and that spark plug costs $24.25 (also amazon prime) (model: Bosch 15717 Oxygen Sensor, OE Type Fitment). There is also a Bosch 12014 Oxygen Sensor for $15 shipped, but I'm not even sure if these parts are compatible with each other.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 04/10/12 at 22:49:36

Id have to go to an auto parts store & have a look at the threads on an 02 sensor. Its it pipe thread, youd be paying way too much,, kinda takin it in the "bung" hole, so to speak,, to pay $10.00 for a bung.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/11/12 at 05:45:47

293630372A2D1C2C1C24363A71430 wrote:

Threads are threads, right? You could *probably* find a big nut that fits an O2 sensor and weld that in instead for a few cents.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 04/11/12 at 07:00:29

Nope, not all threads are created equal. I suspect an O2 sensor would have pipe threads, if so, a pipe coupling can be had for a dollar & a 4"nipple for not much,, heck, if you know the guy at the store & he doesnt mind, you could possibly return the nipple if you dont have a need to keep it,. Every welder I know has a cut off saw,, cutting the coupling down would take all of a minute,,

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by weracerc on 04/11/12 at 07:16:10

forgive me for intruding and offering maybe a stupid idea, but - could you take the bike to a shop with a diagnositc reader like they use here in NC to read the exhaust on the car at annual inspection time (car has to blow clean or no pass inspection)...shove the probe up the tail pipe deal and get the readings as a baseline maybe a cheap simple way to get the process started.....the only reason i offer this is because my brother in law has a shop and he does my car inspections - perhaps if this would work I will get him to "sniff" the bike with the probe and tell me whether my bike is rich or lean....sorry in advance if this is too stupid or way too off base.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/11/12 at 08:13:44

3F30756770676163686537060 wrote:

Nope, this is the kind of stuff I want to hear. cheaper is always better and free is best!

Concerns with this method: how far up does the probe have to go? would a reasonable shop charge me for this? This would only be able to test the bike at a stand-still, but I could probably check all the fuel circuits (idle to WOT) reasonably well. You'd imagine a shop might do this for free, but they do charge for emissions inspection here (PA) so who knows.

I'd be curious to see what requirements the probe has to be accurate (how far up the tail pipe, how long it has to be there, is heat an issue, etc.).

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 04/11/12 at 08:53:49

Maybe call around & see if anyone who runs a dyno could test that while you run it thru its paces? YES, I know,, it breaks on of the 10 commandments
Pay not for services which you can do for yourself,,

But it mite be a good starting spot,, then you could go & diddle with it & take it back & re-run it ( followup runs are generally at a very low price, like $10.00,, ) & se what all that diddling gained you.

The guy I talked to told me if I ran mine on it, he coul;d tell me what jetting changes to make, I could come back & rerun it for cheap..

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/11/12 at 12:43:23

Bought the cheap-o O2 sensor off amazon for $15 (http://www.amazon.com/Bosch-12014-Oxygen-Sensor-Fitment/dp/B0009IK7YC). Hopefully it doesn't take too long to get here.

It looks like it only has a single wire out, which means that that wire is the positive lead and the negative/ground lead is the exhaust pipe/engine/frame.

My plan is to toy around with the sensor before doing anything irreversible to my header to see if I can get any sort of voltage out of the thing, maybe stick it up the tail pipe and see if that changes anything. Then I'll take it to Lowe's and hunt down a cheap fitting for it, because on second thought, $11 for a glorified nut just seems wrong. I'll bother some buddies of mine with welding skills if I can coerce them into doing me a favor and if not, to a pro welder I go.

here's hoping everything turns out decently over the next week.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by bill67 on 04/11/12 at 15:37:25

My carb is and air fuel meter 8-)

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/12/12 at 08:17:31

Got some advice from a buddy at work that did this for his Nova. There is a lot more theory here than I was anticipating, a lot of which I can't use. Supposedly there is a "sweet spot" for O2 sensors, typically in a short pipe right after the collector for all the headers. We've only got one header, so that makes things simple, but we've also only got maybe a foot of viable length on the header to weld anything in.

I was also told a high-end multimeter should have capabilities to record a graph of voltage output from the O2 sensor. Don't expect me to go drop $400 on one though, perhaps there is one at work I can borrow for an evening....

He talked me into trying to do this myself, rather than take it to a welder. Picked up a 115v MIG welder (flux core only) that I'll try to experiment with. Good thing is that if I royally screw anything up, he should be able to repair just about anything for the cost of a bottle of American Honey whiskey (which, by the way, is mighty tasty on its own or in a glass of iced tea 8-) ).

To sum up: the idea is sound and feasible, though it can get complicated if you want to do it "right" and I'm going to try and fumble my way through welding this thing in myself in the hopes that I don't muck it up too bad :-/

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by mpescatori on 04/12/12 at 23:49:21

My two cents' worth.

The Suzuki Savage uses a Mikuni carb; I personally do not know whether this is a "constant airflow" or a "constant vacuum" carb, but I do know that, when it comes to classic cars, there are two fundamental schools of engineering:
- Dell'Orto Carbs - which includwes Webers and Solex, and similar licensed designs,
- SU (Skinner Union) Carbs - which includes many Zenith-Stromberg units.

I do not know how Holley carbs are designed, but the Savage doesn't need a triple or more... ;)

The interesting point is that a properly adjusted SU (whether the old school SU HS or the more recent SU HIF) actually has more fuel-adjusting points than an entry-level EFI unit.

http://www.sucarb.co.uk/

This means that a properly jetted SU HS2 or HS4 (1 1/4" or 1 1/2" slide and butterfly, respectively) may well prove to be more suited,
especially for a vehicle which rides/drives mostly in a mountainous area, where changes of altitude (and AFR) are the norm.

SU HS4 (external float chamber)
http://www.minispares.com/images/products/600/C-AUD640.jpg

SH HiF4 (integral float chamber)
http://www.paltech1.com/sitebuildercontent/sitebuilderpictures/2-23011.jpg

All this may be quite beyond Spacepirates' interest... he lives in Florida...
...but to someone living in the Rockies it might be food for thought.

:)

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by Halvor on 04/14/12 at 00:46:19

Hello. My next mod plan is to integrate this meter into the headlight. I will mount the sensor right before the silencer.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/16/12 at 06:32:58

Didn't end up having enough time this weekend to do much but try to adjust the jetting on the savage (which turned out poorly, by the way).

Girlfriend is going out of town for two weeks though, so that should give me plenty of time to pay more attention to my bikes.

The O2 sensor did come in the mail on Friday. I took it to Lowe's and tried to find a nut to fit the threads. They only had one 3/4 inch nut, but the threads were too coarse on that (I think it was a 10 count thread). Oh well, the hunt continues. maybe an auto-parts store will have something.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by RidgeRunner13 on 04/16/12 at 06:42:39

K&N sells a complete kit for this, and O'reillys' has a couple of different gauges that don't come with O2 sensors.

For the 'nut', just go to a salvage yard & find a section of pipe after the cat. that you can cut out & get it from. You may even get lucky & find a piece of pipe you can use between the head pipe & muffler. 8-)

I don't know if your idea of cheap is $50 or $250, but you could put together something for under $100 using salvaged parts.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 04/16/12 at 07:13:09

Surely there is a wholesale nut & bolt sales place in town,, They can find the size & thread pitch you need, Are you sure its not pipe thread? Is it tapered?

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/16/12 at 07:16:23

7E45484B497E594242495E1D1F2C0 wrote:

Yeah, my idea of cheap is <$25, ha ha. the salvage yard is a good idea, I hadn't thought of that one...

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/16/12 at 07:24:21

302F292E33340535053D2F23685A0 wrote:

Surely there is a wholesale nut & bolt sales place in town,, They can find the size & thread pitch you need, Are you sure its not pipe thread? Is it tapered?

you love pipe threads! ;D

There most likely is a nuts & bolts place around. heck, there are probably a dozen of them, I just can't think of any off the top of my head. 80 degree weather today, maybe I'll take a detour after work and hunt around for one a little bit. That's the good and the bad about Pittsburgh, we've got whatever you're looking for, but it is probably hard to find and a pain in the neck to get to ;) That's what you get for trying to put a major city between a bunch of hills and three rivers. a big 'ole mess of streets.

The thread on the sensor isn't tapered. I *think* it might be 3/4-16, but I wouldn't bet more than a few bucks on it. I'll upload a picture when I get home.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 04/16/12 at 10:57:28

Find bolts & lay thread into thread, or, grab a tool, they make a diameter/pitch tool. Not uncommon to see them hanging in the nut /bolt department.

Your SURE it aint a pipe thread? Reeaaalllyyy?? :)

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/16/12 at 11:16:59

637C7A7D60675666566E7C703B090 wrote:

Lowe's only has the pitch tool that has sample bolts and nuts that it carries on the wall, so no luck for me there.

and man, i don't even know anymore. I've been thinking about this so long i've confused myself. I'm going to have to eat my shoe if it ends up being pipe thread...

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 04/16/12 at 11:37:01

I went & looked at some online,, not pipe thread,,
What size wrench fits it?

You cant get the info you need from the place you got it?

What vehicle would it fit?

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/16/12 at 12:23:52

I love how half of this post is just about these stupid threads...

Don't know about the wrench, I'll let you know when I get home.

Nope, amazon just says "OE" fitment (original equipment).

There are dozens of vehicles. Primarily GM brands, late 80's to early 90's. http://performance-curve.com/12014-boscho2sensorforgm.aspx has a full list if you're curious. Probably SAE and not metric if that is what you were thinking.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by SALB on 04/16/12 at 13:26:14

They make universal weld in bungs just for this purpose. You should be able to get one at the local exhaust shop or auto parts store. Just be sure to take the O2 sensor with you. I think they also sell plugs, so you can remove it when your done and not have to keep changing your setup. :)

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/16/12 at 19:39:44

64676470666E60050 wrote:

Good idea. I'll stop at AutoZone on my way home from work with the O2 sensor to see if they have anything.

To answer JoG about the size of the O2 sensor, the hex part of the sensor is either 22mm or 7/8 inch. I can't tell which, they both fit decently well. I'm kind of annoyed that the hangup on this project is finding a friggin nut. bah. oh well.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 04/16/12 at 22:31:27

Man, Ive tried, I really have, but I thnk that Salb dude has the answer,,

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/17/12 at 05:45:59

352A2C2B3631003000382A266D5F0 wrote:

Man, Ive tried, I really have, but I thnk that Salb dude has the answer,,

and I appreciate it.

he couldn't ring in a few days ago, could he? noooooo, gotta wait till the bitter end and slip that bit 'o knowledge in here ;)

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 04/17/12 at 08:37:54

Yeaa,, I know,, I need a "Slap that guy!" emoticon,,

Where the HEKK you been Salb? Coulda saved me a load O hassle,,

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by SALB on 04/17/12 at 16:28:47

Sorry. :-[ Been soaking up the rays. Spring is FINALLY here! ;)

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/17/12 at 17:26:31

negatory!

Went to AutoZone this evening, no luck. Even got me a confused look when I asked for a "weld-in O2 sensor bung."

Checking online, and they are $16-$20! what the crap?!

Ugh, and to make things WORSE, I look online and see that a number of these weld-in bungs for O2 sensors have JoG's favorite acronym next to them: NPT.

to be fair, I had limited time at Lowe's last time I went, so I'll try there AGAIN and check PIPE THREADS this time :-[

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by verslagen1 on 04/17/12 at 17:35:19

yeeeeah. ::)

http://www.ebay.com/itm/O2-BUNG-OXYGEN-SENSOR-MILD-STEEL-O2-EXHAUST-PIPE-BUNG-WELD-BUNG-/150788859442?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item231bb76632

http://www.ebay.com/itm/AEM-3-No-Weld-o2-Sensor-Bung-/280760996057?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item415ea8d0d9

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 04/17/12 at 20:18:58

If you can find a pipe coupling that fits, then cut it in half & weld it on.,

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/18/12 at 07:59:44

This thing is really getting on my nerves. I need a friggin nut that fits this friggin O2 sensor, and it is difficult to find one that is a reasonable cost.

There are multiple thread sizes and pitches for O2 bungs, so I can't even be sure that what I'd be getting is the right size.

What I really should have done was bought a tap and die set to verify the size/pitch of this thing and then ordered an appropriately sized nut/bung and bolt/plug.

I'm just extra pissy because I fouled out a plug on my bike after work yesterday and drained the battery trying to start it. I had to take my car into work today, and who likes doing that when the weather is 50 in the morning and 65 in the afternoon? I hate missing good riding days :'( oh well. soon the weekend will be here. and I can't really complain, the early spring has given me a lot more riding than is normal.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 04/18/12 at 09:22:31

Dude,, take that thing to a nut & bolt shop[.. seriously..youre makin way too much of it,

Or go to the plumbing section of a hardware store & pick up a piece of pipe & lay the threads together & see if the pitch matches,

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/22/12 at 20:29:13

bought a bung and plug off amazon without knowing if they'd work. Turns out they did.

I had an hour this afternoon so I welded the bung in. Not the prettiest work (especially since I just cut a hole in my wrap instead of taking it off, ha ha) but it should be functional enough. Don't know if I got it air tight, as I ran out of time. I drilled a hold in my header (about 8" higher than the foot peg, facing backwards) and used a hammer to flatten the header a bit. I then welded the bung in. Something must have happened to the lower threads of the bung, as the plug doesn't seat fully anymore, but the O2 sensor does.

Tomorrow looks like a high of 37 or so (what the heck happened to our early summer? it was a high of 80 just a few days ago!), but I should at least be able to start her up and see if she leaks. boy I hope she doesn't leak.

Anyways, damage done. I'll take pictures tomorrow along with testing out of the O2 sensor works or if I just blew time and money on some garbage.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by LANCER on 04/24/12 at 10:13:41

I've been mostly absent from this thread and missed out on some of the frustration.
I understand totally trying to save $$ on a setup; I did the same but the no-name meter I finally found on ebay was not workable for me since I could not figure out what wires from the meter went where.
I ended up getting this K&N kit, but have yet to install it.
One of the many things waiting to be completed.

Below is the Kit from K&N that has everything needed.
Retails for just under $300 ... yea, crazy.
Online direct price of $210.99

My dealer cost for this kit is about $150-160 if I remember correctly.
If anyone wants one I will sell them for my purchase and shipping cost.

http://store.knfilters.com/search/product.aspx?Prod=85-2441

K&N 85-2441
Performance Products - Round Air/Fuel Ratio; Complete
K&N Air/Fuel Monitors and accessories are designed to help performance enthusiasts calibrate an optimum air/fuel mixture ratio. The monitor will work on carbureted, injected, supercharged or turbocharged engines using unleaded gasoline, alcohol, propane or nitrous oxide. It will not work with nitromethane or diesel fuels. Using the instrument to monitor the engine’s air/fuel mixture ratio, a tuner can adjust for power, economy and/or improved drivability. [MORE]

http://www.knfilters.com/images/l/85-2441.jpg

85-2441 List Price: $ 293.86
Your Price: $ 210.99

You Save 28.2%

K&N 85-2441 Product Specifications
Product Style: Accessories
Weight: 0.54 lb (0.25 kg)
Product Box Length: 12 in (305 mm)
Product Box Width: 9.06 in (230 mm)
Product Box Height: 2.5 in (64 mm)

K&N Store Inventory Status
In stock

Additional Information
Installation Instruction Sheet
Installation Instruction Sheet
Large Picture
Medium Picture
Small Picture

K&N 85-2441

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 04/24/12 at 10:33:30

I look at things like that & wonder

"How do it KNOW?"

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/24/12 at 11:28:21

3C2325223F3809390931232F64560 wrote:

I look at things like that & wonder

"How do it KNOW?"

Well, since you asked...
The zirconium dioxide, or zirconia, lambda sensor is based on a solid-state electrochemical fuel cell called the Nernst cell. Its two electrodes provide an output voltage corresponding to the quantity of oxygen in the exhaust relative to that in the atmosphere. An output voltage of 0.2 V (200 mV) DC represents a "lean mixture" of fuel and oxygen, where the amount of oxygen entering the cylinder is sufficient to fully oxidize the carbon monoxide (CO), produced in burning the air and fuel, into carbon dioxide (CO2). An output voltage of 0.8 V (800 mV) DC represents a "rich mixture", one which is high in unburned fuel and low in remaining oxygen. The ideal setpoint is approximately 0.45 V (450 mV) DC. This is where the quantities of air and fuel are in the optimum ratio, which is ~0.5% lean of the stoichiometric point, such that the exhaust output contains minimal carbon monoxide. (from wikipedia: http://en.wikipedia.org/wiki/Oxygen_sensor#Zirconia_sensor)

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/24/12 at 11:41:39

Those kits make me wonder what makes them worth it. $300 asking price is STEEP. Especially if the parts add up to not much. The real variable here is the O2 sensor itself. I got mine for $15, but some are hundreds alone.

LANCER, if you give that "scirocco" link in the first post another gander, it looks pretty similar to what you posted. I'm curious as to why the cost is so high. Maybe that O2 sensor is much better than what I picked up? The circuitry to light up some LEDs based on a voltage is fairly minimal, so I can't imagine much cost there. Maybe it is just rarity?

I dunno, that's cool that you've got a kit and will offer it up like that.

As for O2 wiring diagrams... this might help: http://www.ngk.com/glossaryImage.asp?imgID=309 and http://www.aa1car.com/library/o2sensor.htm

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by SALB on 04/24/12 at 11:54:56

Generaly speaking, wide band and heated sensors are more money. Specific fit sensors with the factory connecters are also more money.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by LANCER on 04/24/12 at 17:44:14

4B484B5F49414F2A0 wrote:

Generaly speaking, wide band and heated sensors are more money. Specific fit sensors with the factory connecters are also more money.

Y E P

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 04/24/12 at 18:11:57

& selling a turnkey outfit ( convenience) costs mo mun nee..
Not everyone has the time, or ability to do a DIY unit,, And, If they do the DIY & they have their time & $$$ in it & it doesnt work,, they really dont have a warranty department to go to.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 04/26/12 at 06:49:17

I promised pictures, so here they are, albeit late:
http://https://lh5.googleusercontent.com/-8o94fdy5O1w/T5lCQ-20wxI/AAAAAAAABNs/eTucgdJMbBc/s144/2012-04-25%252016.31.52.jpg
(for bigger image: https://picasaweb.google.com/lh/photo/bXXWTsekeWD_YkHd42xGKNMTjNZETYmyPJy0liipFm0?feat=directlink)

another angle: https://picasaweb.google.com/lh/photo/OhtqhDuBzeW5WPbDHGEImdMTjNZETYmyPJy0liipFm0?feat=directlink

and what was causing some rattle in my exhaust:
https://picasaweb.google.com/lh/photo/FF_tzVrWZSUx-ZSIVP_KXtMTjNZETYmyPJy0liipFm0?feat=directlink

I haven't had a chance to test out the O2 sensor yet, but it doesn't seem that the bung leaks. can't tell from putting a hand around it or from a change in exhaust behavior. There are plans to grind down the weld (not too bad for my second time welding, i guess) and clean it up a bit, after which I'll put some water on it with the bike cold to see if it bubbles. The weather has become cold(er) and wet(ter), not sure what that means for getting out and testing it. I did take the bike to the bar last night, but I didn't exactly what to take my multimeter with me. maybe I'll take it tonight, i'm going to look at a 1979 GS850 which are notorious for electrical woes anyways.

EDIT: oh yeah, forgot to explain the muffler rattle. I had been hearing a metallic rattle at random times on the bike. I orginally thought it was clutch related as I would only hear it when actuating the clutch, but it turned out that that was the only time the engine was quite enough AND thumping enough to allow me to hear the rattling. When I took off the exhaust to drill/weld it, a hand full of those baffle tabs fell out so I looked inside and I could see that the baffle had cracked in half and collapsed on itself. lovely. This probably happened a solid year ago, so I'm not too concerned about it, just kind of amusing.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 05/04/12 at 13:29:01

it works! I guess. My bike has been acting tempermental in the warm weather at idle, and the O2 sensor is giving a reading of .86 volts!

Pulling the plug later tonight after the bike cools to verify that i'm overly rich.

Ordered $5 of parts from digikey (voltage rectifier, led bar graph, led bar graph driver) yesterday, so they'll hopefully be in middle of next week. I'll get that rigged up on my bike and see how the rest of the throttle range reads.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 05/04/12 at 16:04:12

So, your experiment is, by all indications, a success! Great news,,, gotta love it when ya do a DIY on that kind of a project & win,,
Now, for the Big Evaluation,,

How much is a kit? How much have you got in it? How much time have you got in it? Not to the minute, but kinda sorta, planning, shopping, & hands on doing it? The nice thing is, what youve done is prove it can be done, so, the planning/designing & shopping time is handled for anyone who wants to follow your path. So, I could come in behind you now & just buy the stuff & go to work,, some drilling, welding, wiring & riding . Whoever follows will benefit greatly & save some $$$. Congratulations!

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by Boule’tard on 05/04/12 at 19:15:46

5A454344595E6F5F6F57454902300 wrote:

Now, for the Big Evaluation,,

How much is a kit? How much have you got in it? How much time have you got in it? Not to the minute, but kinda sorta, planning, shopping, & hands on doing it?

+1 How much money might one save if they were to copy you? :D

Awesome work. I admire the tenacity.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 05/05/12 at 08:20:40

2F22382128392C3F294D0 wrote:

[quote author=5A454344595E6F5F6F57454902300 link=1334080904/45#54 date=1336172652]
Now, for the Big Evaluation,,

How much is a kit? How much have you got in it? How much time have you got in it? Not to the minute, but kinda sorta, planning, shopping, & hands on doing it?

+1 How much money might one save if they were to copy you? :D

Awesome work. I admire the tenacity. [/quote]

Ha, I'd have to look through my records to get you an exact number, but a good estimate is around $35 assuming you already have the tools required and some odds and ends here and there. I can't speak for the total time to get the LED gauge hooked up, but the O2 sensor was real quick to get installed with the drilling/welding. It took me maybe an hour total; someone who is more experienced welding would take much less time. I expect the gauge to take another hour or two, depending on what level of polish I apply to it. I'm more of a "function over form" kind of guy though, so I'm fairly sure it'll be butt ugly. Research was the big time sink, that and a few wasted trips to part stores to find a fracking bung/nut/whatever.

The odd thing about the "kit" is that there are so many combinations that could work, and I really haven't tested my setup (or any other setup) fully, so I'd hesitate to recommend anything just yet.

A downside to this "mod" is it doesn't necessarily gain you anything. In the end, I'll have something that'll tell me if my jetting is off, but the vast majority of people on this forum can already tell that by how the bike rides, how it sounds, etc. I don't even think I'll end up keeping the LED gauge and O2 sensor hooked up for long; I just want them in there long enough so that I can get my bike as close as possible to the right jetting.

Thanks for the encouragement, guys. I have a lot more respect for How-To's on this site that have all sorts of pictures and contiguous steps. I took my sweet time with this (and it is still on-going!), so to have a definitive guide on anything that well documented is impressive.

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by justin_o_guy2 on 05/05/12 at 11:40:50

A downside to this "mod" is it doesn't necessarily gain you anything.

It does more than "Your jet is wrong". It will tell you at what point in the throttle/rpm its wrong & tell you if its lean or rich, right?

If it proves out & you are able to get your carb set up as right as a carb can Be set up,, (you know,, todays temp/humidity/barometric pressure was great,, what will it be tomorrow? ) & you can help others do it & avoid that Time Sink of figuring what stuff to get to create a working match up, I think spending less than $50.00 & having an O2 reader on the bike is killer,,
Does it stay with the bike all the time or is it just a diagnostic tool to hit it with every once in awhile?

Title: Re: Is it possible to make a cheap DIY Air Fuel Me
Post by spacepirates on 05/05/12 at 15:56:33

Yes, it'll tell you in what throttle range if you're lean, rich, or spot on. I'll be interested to see how the LED gauge acts when I get it on.

The sensor sticks out of the header three or four inches straight back, but it isn't intrusive at all. I wire-tied the wire output of it to my crash bars, so that stays out of my rear brake pedal. It has been on the bike for a while now, so it could be permanent. If the LED gauge mounts somewhere and doesn't look horrible it very well might stay on the bike a good long while.