SuzukiSavage.com - Print Page

SuzukiSavage.com
/cgi-bin/YaBB.pl
General Category >> Rubber Side Down! >> Wide open woes
/cgi-bin/YaBB.pl?num=1518555823

Message started by Shrulk on 02/13/18 at 13:03:43

Title: Wide open woes
Post by Shrulk on 02/13/18 at 13:03:43

Hello all, noob here. I've searched a ton of pages while waiting for my account to be approved. 01 savage stutters bad and starts getting choppy at anything over 1/2 throttle. Doesn't matter the gear. The bike is modified with big open air filter and a shorty baffled turn out exhuast off the header pipe. I've tried jets and fresh gas. Have a raptor petcock on the way as well as a carb rebuild kit. This has me completely stumped. It starts great and will free rev as high as you want it to. Nothing seems to change this issue. At idle to 1/2 throttle under load is good and peppy. Any help and ideas are appreciated.

Title: Re: Wide open woes
Post by batman on 02/13/18 at 15:16:14

You only have two problems 1) your air cleaner is mounted right on the carb. 2)you've replaced the stock muffler with something worse. Don't feel bad it's a been done by lot's of newbees. Your exhaust is doesn't give the needed back pressure the motor requires,so you have mid range sag , it acting like a straight pipe ,and that's very hard to tune the carb to. Read up on it in the Tech Section .(On the right when you come on the site).

Title: Re: Wide open woes
Post by sawkuh on 02/13/18 at 16:13:02

Id agree with above, based on the brief description. With that air cleaner and exhaust air is coming and going with ease. Id start with the question "what jets are in the carb?" If its the stock jet (147.5 I think) it's a no brainer where you need to start.

Title: Re: Wide open woes
Post by Gary_in_NJ on 02/13/18 at 17:16:25

We need more info. More then likely it's a carb issue, but we need to know your jets, needle position, where you live, the condition of the air cleaner and what your oil smells like.

Title: Re: Wide open woes
Post by batman on 02/13/18 at 22:41:38

It starts where everyone doing mods should. with the exhaust. the motor has to be able to breath out before it can breath in. One of the most important factors is the length of the header pipe which is 32"(stock) this gives us a torque peak a 3400rpm.(mid range). with the muffler he running it acts to extend the header (there is no solid baffle in it's center) ,short headers run better at higher rpm ,long headers perform better at lower rpm. that's why is bike runs good until he hits mid range (40 mph ) then sags ,his " header" is now about a foot longer., and falls outside the limit of normal for a 650cc motor which is 30' to a max of34'', a normal muffler provides a larger space at the end of the header ,that provides the proper length for wave tuning which can also add hp at certain rpms but that is also dependent on a header length of 32 " not 44 ".I don't think He 's aware of the spacer mod ,nor has he gone to larger jets , so he's experiencing a lean sag at mid range.he may put larger jets in and be rid of the sag but I think his mileage will take a big hit.

Title: Re: Wide open woes
Post by Shrulk on 02/13/18 at 23:22:30

The air filter is not directly on the carb, it's on about 10 inches of tubing to make the filter sit behind th battery box and off to the side. The jets currently are 55 pilot and 150 main with the white spacer put back in. I've tried 147.5, 150, 152.5 and 155 main jets as well as trying to do the spacer mod with the washers from the ryca jet set. 1st tried all 3 then tried 2 with very little change so I put the white spacer in for the purpose of trouble shooting. This issue isn't like the normal no more power because it flows to much, it's more like it's not getting enough fuel. I've tried running on PRI and ON with no changes. As soon as the carb rebuild kit shows up I'll be blowing every little orifice out. The oil is fresh just changed it when I did the head bolt hole plug non sense

Title: Re: Wide open woes
Post by Yoshi on 02/14/18 at 03:08:27

The stock petcock could go bad, have you upgraded to a raptor petcock yet?

Title: Re: Wide open woes
Post by Gary_in_NJ on 02/14/18 at 05:41:44

Get your new petcock installed and see if the problem clears. Also, if you have an in line fuel filter installed, remove it.

Title: Re: Wide open woes
Post by verslagen1 on 02/14/18 at 07:10:22

023923243D3A510 wrote:

The raptorcock will probably fix you up.
Here's what happens with a free flowing air filter and exhaust... your vacuum goes to hell at about 1/2 throttle and won't hold the petcock open.

Title: Re: Wide open woes
Post by Shrulk on 02/14/18 at 08:27:17

Raptor thingy is on its way, no inline filter. I appreciate the help so far amd look fprward to sharing my build and learning more about these bikes. I read that the slide is vacuum operated so I have a bit of a hunch between the loss of vacuum, weak petcock and older carb these ideas will help. I will check out the diaphragm on the side of the card when I do the rebuild. Hopefully not have to spend $100+ on a new slide. Mine looks a little worn

Title: Re: Wide open woes
Post by batman on 02/14/18 at 08:56:33

I'm going to guess that if he's run the petcock on pri. while trying all those jets and the spacer mods,without any change, that the raptor isn't going to help.but a decent muffler would.

Title: Re: Wide open woes
Post by Dave on 02/14/18 at 09:01:01

One of the interesting traits of the low powered Savage, is that when cruising at highways speeds you can actually get into a situation where you have the throttle open far enough that the main jet is working for extended periods. (Most cars, trucks and motorcycles have so much power that they are only using a fraction of the available power at steady cruising speeds).

When the throttle is opened more than 1/2 and you are using the main jet circuit - it requires a number of things to be working properly. Fuel flow needs to be steady (petcock, fuel line, float needle/seat, fuel tank vent), the carb circuits need to be clean and the jetting properly sized, the ignition system (spark plug, coil, ignition box, battery, charging circuit) needs to be able to provide a good spark, and the air cleaner needs to be able to provide the needed air supply.

Title: Re: Wide open woes
Post by Shrulk on 02/14/18 at 09:44:50

I did drain the tank a few days ago to check the filter screen on the petcock and used the PRI set to g and seemed to only drain at about half the flow I was expecting even when I pulled the fuel cap. Maybe a dumb question here but if I leave the petcock on PRI while it just sits for days will that cause the carb to leak or or not. It doesn't as of now so I'd assume the float is working right? I hav pulled the fuel bowl a few times after it setting so I could change jets and the bowl is only about half full. Sorry for so so many questions

Title: Re: Wide open woes
Post by batman on 02/14/18 at 10:49:50

While it would be a good idea to check the float height, ,a half full bowl level sounds normal ,the jets and the float taking up the rest of the room in the bowl. your float valve is holding or you would have gas coming out the vent lines.

Title: Re: Wide open woes
Post by justin_o_guy2 on 02/16/18 at 10:29:00

The stock Petcock is known to cause difficult to understand problems.
The Raptor is cheap and easy to install.
The fuel level can be checked with a piece of tubing on the nipple on the bowl drain, held up next to the bowl.
The fuel should be at the top of the bowl.
If it's slow to fill and low in the first place, you're gonna be spitting and sputtering at open throttle settings.

Title: Re: Wide open woes
Post by Shrulk on 02/16/18 at 14:42:39

The raptor thingy helped but didn't fix all the issue. Carb will be rebuild this weekend and bigger jets are on the way.

Title: Re: Wide open woes
Post by justin_o_guy2 on 02/17/18 at 07:22:03

Why do think you need bigger jets?
If your bowl isn't full , it's not gonna run right.
Do you honestly think that carburetor, those jets , off the showroom floor, ran like that?

Title: Re: Wide open woes
Post by Gary_in_NJ on 02/17/18 at 08:09:16

Yeah, a fuel height test is in order as the next logical step.

Title: Re: Wide open woes
Post by batman on 02/17/18 at 10:41:21

JOG , I think he will have to go to bigger jets if he 's going to get rid of that mid range sag . Yoshi had a similar filter and muffler set up on his bike and used a 55 pilot ,152,5 main and two #4 washers for the spacer mod.( their elevations are nearly the same) I don't think mpg will be good ,but it may run better . If he can't live with the bad mileage then it's time to think about a better muffler and smaller jets.

Title: Re: Wide open woes
Post by Shrulk on 02/17/18 at 14:13:37

I will do the fuel bowl level test before I pull the carb for a rebuild. I'm not to concerned with the mileage just want to try to optimize the throttle range with the air filter and exhuast set up i have. It struggle to get up to 50mph and is a dog and stutters on hills.

Title: Re: Wide open woes
Post by Gary_in_NJ on 02/17/18 at 15:04:55

Old carb tuners like me always say "jet for throttle response", not fuel mileage.

Title: Re: Wide open woes
Post by batman on 02/17/18 at 15:17:30

Just changing the jets won't cut it ,you have to do the spacer mod or still have the mid range sag you have now.

Title: Re: Wide open woes
Post by Shrulk on 02/17/18 at 16:36:57

Here's the update. 55 pilot, 152.5 main, cleaned carb and rebuild, 3 of the #4 spacers for the white spacer mod, new idle mix screw at a little over 1 turn out from the full closed setting and adjusted the float just ever so slightly and now I feel like a complete jack a$$ because it runs about 90% better. Thank you all for every tied bit of ideas and knowledge. I'm hitting 70mph pretty easy but still have a little stutter ad full twist. It really is a huge difference just from a few hours ago.

Title: Re: Wide open woes
Post by Dave on 02/17/18 at 16:54:29

If you can turn your idle mixture screw all the way in and the bike runs....the pilot jet is too big (turn the idle speed down a bit before you try to adjust the idle mixture screw....then turn it back up to 1,100 rpm idle for riding).

Title: Re: Wide open woes
Post by Shrulk on 02/17/18 at 17:26:42

Yeah I was wondering that. I did put a larger pilot jet under the slide diaphragm. Guessing I should put the one I pulled back in it and start there

Title: Re: Wide open woes
Post by Shrulk on 03/01/18 at 12:13:05

Ok so I did some back tracking today. I pulled carb and verified i ha e 50 pilot and 150 main jets, blew it all out with air, adjusted need to the spacer mod position, 1.5 turns on air mix and double checked float level. Now i had a theory, the slide is vacuum operated and the slot in the top of the i take side of the xarb is what opens the slide........ big air filter and 10 inches of silicone tube for my i take creats very little resistance.... so I pulled the after off and left the tube, put tape over 2/3rds of the opened of the tube to create less Opening and man this bike has changed. I can pull 80 with with some left to twist. I can pass cars and it'll almost toss me off when hitting 4 and 5th gears. Time to get an a new filter setup or just get a small ryca or such cone. Thank you all for bearing with .e and giving me input. The bike looks and sounds the way I want and I'm friggin stoked

Title: Re: Wide open woes
Post by batman on 03/01/18 at 20:21:22

Don't get stoked to soon! Changing the air filter will do little to effect how the bike runs!(you'll be right back where you started) When you put tape over the inlet it cut down the amount of air drawn into the carb and increased the vacuum in the carb body, which pulled more fuel from the jets ,which should tell you your jetting is way to lean . That's your problem! not what air cleaner you use. I'll run this by you one more time 55 pilot ,2 # 4washers on the needle ,152.5 -155 main jet. Don't expect good mpg.

Title: Re: Wide open woes
Post by eau de sauvage on 03/02/18 at 00:01:59

Make sure all important connections have been inspected too. No harm in unplugging say the signal generatore at the plug and spraying with electrical contact cleaner. I found that on top of a major fuel issue that there was this other smaller thing which I didn't discover till I replaced the carburetor which fixed the main problem thus then exposing a curious intermittent fuel starvation. Turns out that cleaning the contact as above fixed it.

Title: Re: Wide open woes
Post by batman on 03/02/18 at 13:18:06

At one point you said you changed to a larger jet under the slide diaphragm ,these jet(s) should be left alone ! one is the pilot AIR jet ,the only pilot jet(fuel) to be changing is in the carb bottom next to the main jet.

Title: Re: Wide open woes
Post by Shrulk on 03/02/18 at 18:07:38

I fabricated a mild restrictor plate for the air tube, the jets under the slide diaphragm have been put back to stock. Have risen the bike a few times yesterday and today and it's running great. I will be playing with the main jet a little over the next few days and try to find the sweet spot

Title: Re: Wide open woes
Post by IslandRoad on 03/02/18 at 18:19:12

4C776D6A73741F0 wrote:

I ... Have risen the bike a few times yesterday and today ...

For a minute there I thought, holy hell, he's got it poppin' wheelies!! Then I realised ... auto-correct :-?

Title: Re: Wide open woes
Post by batman on 03/02/18 at 20:05:00

A restrictor plate use is unheard of, a stock bike runs 85-87 mph, I doubt you'll make it, hope you don't burn the valves trying ,but I guess some prefer learning the hard way. Let us know how blue your header pipe is turning.