SuzukiSavage.com
/cgi-bin/YaBB.pl
General Category >> Technical Documents/Reference >> Test your Petcock,.. don't just turn it to Prime..
/cgi-bin/YaBB.pl?num=1251932429

Message started by Serowbot on 09/02/09 at 16:00:29

Title: Test your Petcock,.. don't just turn it to Prime..
Post by Serowbot on 09/02/09 at 16:00:29

Note: Please post questions in the Rubberside or PM me...

...a faulty vacuum operated petcock can cause either a flooding, or starvation problem, depending on the failure...
...both are very common, and they can both be dangerous...

So,... here's how to check your petcock,...

Check the vacuum line that goes from the rear of the petcock to the right side of the carb (Hint: it's usually covered with a chrome spring).  
If it has any fuel in it at all,... the petcock diaphragm is leaking and needs to be replaced.  You may have to give a light suck on the line to find out for sure (not kidding,... it may only leak when vacuum is applied).... (This will only test for flooding, or rich, sputtering issues)...
If you don't find any fuel in it,... you're not done... you need to go on to the Prime and cap test...


54777F7D7E77777E691B0 wrote:
Note from Moderator...This "Prime & cap" test should be run for at least two tankfuls of gasoline to give it enough time to test for occasional fuel starvations and the slow diaphragm leakage issues.  You must run it while intentionally trying to repeat the issues you have been having, plus running your normal traffic patterns over a period of a week or so.

 
To do the Prime and cap test, start by pulling the vacuum line off at the intake port on the carb, and blocking it, and the line that connects to it coming from the petcock ...(Note: just pulling the line will create a HUGE vacuum leak,.. BOTH ENDS MUST BE CAPPED!)...


http://i600.photobucket.com/albums/tt82/serowbot/plug.jpg?t=1251936339
Then ride, with the petcock set to prime, and see if it runs better... If it runs better, the petcock is bad...

The vacuum petcock can be the cause of both,...
...fuel starvation,(if the vacuum diaphragm does not hold the fuel line open, to let fuel flow)...
...or flooding, (if the diaphragm leaks, and lets fuel run down the vacuum line, directly into the intake)...  
... in the former case,... if you have been experiencing fuel starvation,... particularly at highway speeds... you may be able to cure the problem by replacing the vacuum hose, or tightening the fittings... maybe...
...in the latter case, if the diaphragm is ruptured, fuel will fill the airbox and crankcase,(in which case you must drain the oil and replace it, and clean the airbox and dry out the filter)...

If you find gas in the vacuum line, or if it runs better in the test,...
...you have four options....
-replace with a new stock petcock,... ($80.00)
-rebuild it (Versy has instructions for this, also in the tech section),... $25.00)
-convert stock petcock to manual,... (free, but work)
-or replace with manual, Yamaha Raptor 660 petcock....($25.00)

... a new stock petcock will run you about $80.00...

Versy rebuild instructions are here...
http://suzukisavage.com/cgi-bin/YaBB.pl?num=1268804471/1

bobo383 has a clever conversion to manual on/off/reserve that has worked well for me,...
http://suzukisavage.com/cgi-bin/YaBB.pl?board=tech;action=display;num=1113631600

...but I eventually went with the Raptor petcock because it also makes tank removal easier....
This is the Raptor part no.  5LP-24500-01-00
2003 Yamaha Raptor 660 YFM660R
http://www.ronayers.com/browseparts.cfm?SearchString=5LP-24500-01-00&adv=5&kw...
NOTE... ( all Raptor 660 petcocks fit,... I included a specific model/year for internet ordering, and anal retentive counter salespeople...) (Raptor 350 petcocks won't fit)...
(also note,...the Raptor petcock clears the frame easily, and makes tank removal much less hassle)...
The Raptor is a direct fit replacement,... just remember to cap the vacuum tap on the carb...


Quote:
How to install a Raptor...
Disconnect the fuel line at the carb, and run the hose into a gas can.  
Turn the petcock to prime and let the gas drain into the can.  
Remove the vacuum line, and block off the vacuum tap on the carb... (use a screw, gas resistant rubber cap, golf tee,.. whatever)...
Remove the old petcock (two screws)...
Install the Raptor with the same two screws..
Connect the fuel line...
Turn Raptor to on position...

PS... if you've had excessive leaking,... change your oil. and clean your air box and filter, before riding)... ;)...


Here's a view of the Raptor petcock installed...
http://i600.photobucket.com/albums/tt82/serowbot/sign017.jpg?t=1288393883


Quote:
If your test is negative for a petcock malfunction,... the likely culprit is a stuck float, or dirty float needle seat.
Before you tear into the carb,... try this trick.
Use the plastic handle end of a screwdriver to tap on the outside of the floatbowl... This will often un-stick a stuck float... ;)...

Title: Re: Test your Petcock...
Post by Digger on 11/23/09 at 21:31:14

Serow,

Well said.....this is a post that is long overdue!  [smiley=thumbup.gif]

There are two basic flavors of petcock problems:  Lack of fuel flow and fuel flow through the vacuum line.  The above test will not tell you which problem you have, but that is a moot point.  Either way, you still need to fix or replace the petcock.

Title: Re: Test your Petcock...
Post by verslagen1 on 07/15/10 at 11:30:02


796F78657D68657E0A0 wrote:
Then ride, with the petcock set to prime, and see if it runs better... If it runs better, the petcock is bad...

If you find gas, or it runs better in the test,... you have three options.... Replace with new stock petcock,... convert stock petcock to manual,... replace with manual, Raptor petcock.....

Actually you have 5 options, add replace vac line and replace diaphragm.  I've had to replace my vac line just about every year.

Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by splash07 on 11/07/10 at 07:49:04

Just got my raptor in the other day and have a couple of questions. First, am I correct in assuming that the vacuum port on the carb has to be blocked? And second, do the raptors work best with an additional in line fuel filter?

Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by Oldfeller on 11/07/10 at 09:52:09


Any parts store has the little rubber boots that go over the nipple in the carb body and yes you do have to block it off.

Here is your tech post with videos for how to put on a Raptor petcock.

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1315418285


===================


Yes, fuel filters are a good thing.

Here is your tech post for a filter mod.

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1211846392


Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by Digger on 11/10/10 at 21:50:16


2A2935382A31696E590 wrote:
....First, am I correct in assuming that the vacuum port on the carb has to be blocked?....



Yes.

And, there are many ways to block the carb's vacuum port.

Here's how I did it.....it's cheap and effective:


http://i235.photobucket.com/albums/ee201/Digger109/CarbVacuumPortPlugE.jpg


I just cut off a section of the existing vacuum hose, squeezed some silicone sealant in it, folded it over, and held it folded with two small zip-ties.  Then, I plugged it into the carb's vacuum port.

Been fine for over a year now.

IHTH!

Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by arteacher on 08/07/11 at 10:45:03



Does the amount of reserve change with a Raptor petcock? If so by how much?

Reserve on a vac stock petcock is 25-30 miles

Reserve on a Raptor is 20 miles

Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by oceantransistor on 08/07/11 at 10:57:16

and finally, what happens when you forget to turn of the Raptor manually?  very bad things right?  I'm sure it's happened?  I'm glad I found this forum, I'm learning alot about the Savage here, way more then any mechanic has cared to insight me with

Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by Serowbot on 08/07/11 at 11:54:54

Nothing bad happens... it is just a safety valve...
It's good practice to turn it off when you park,.... just in the off chance that your float sticks... but, that is a very unlikely occurrence...(in the 1960's and earlier, before o-ring gaskets,... many carbs tended to weep fuel when parked, and shutting off the petcock stopped this)(modern bikes don't weep, unless something is broken)......

It's kinda' like asking,... what happens if you don't wear your seatbelt?...
Do you die?...
No...  only if you are in an accident,.. and that accident is serious,... and it occurs in a way that the seatbelt will save you...

Now,.. I do wear a seatbelt in my car,.. but my bike doesn't even have one, and I definitely wouldn't feel safer if it did...

I ridden bikes for 30 years... 26 of those were on bikes with manual petcocks...  and I only ever turn mine off, to remove the gas tank or do carb work...
I have had a stuck float one time in those years,... but it occurred, while I was riding, so a vacuum petcock would not have prevented it.
... and had I not noticed, a vacuum petcock would have hidden the fact from me until I rode again... That's not safe...
(EDIT ...just remembered, I've had a stuck float twice... second time I was parked, and saw the puddle)... there would have been no puddle with a vacuum petcock, but the float would still have been stuck, and would have continued it's leaking once I started up......
I'd much rather see the puddle of gas under my bike while it's parked, than get on it and find out at 60mph on the freeway...

I've bought, fixed, and sold 6 , and maintained 3 more Savages, plus owning one for 5 years, and seen 4 vacuum petcock failures in that time cause, (not prevent), a fuel leak that flooded the engine and airbox with raw fuel...

A "safety feature" that causes more leaks than it prevents, is not a safety feature...  and you will find no official word from Suzuki that it is a safety feature... it is a convenience feature for those that would forget to turn it on or off...  Many people, even mechanics, think it's a safety feature because they don't understand how it operates...
If your float ever sticks, and you have a manual shut-off... turning that off will stop the leak... a vacuum petcock will do this automatically, (as long as it is working properly), and only once you stop, (not while the engine is running)...
If your vacuum petcock ever leaks... there is nothing to turn it off...  You will have to quickly find some pliers, disconnect the vacuum line, find something to block off the hose, then disconnect the fuel line, and do the same,... all the while gas is flowing, possibly over a hot engine...

A vacuum petcock is an accident waiting to happen...
... about a third of members here have experienced a failure...
... another third probably will in the future...
.. and a last third will get lucky, and not have a problem...


Now, you have to ask yourself a question?...
"Do you feel lucky, punk?...  :-?...
Sorry,... didn't mean to call you a punk... it's just too cool of a quote.. ;D ;D ;D...

Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by Digger on 08/07/11 at 18:37:26


6F796E736B7E73681C0 wrote:
Nothing bad happens... it is just a safety valve...
It's good practice to turn it off when you park,.... just in the off chance that your float sticks... but, that is a very unlikely occurrence...(in the 1960's and earlier, before o-rings gaskets,... many carbs tended to weep fuel when parked, and shutting off the petcock stopped this)(modern bikes don't weep, unless something is broken)......

It's kinda' like asking,... what happens if you don't wear your seatbelt?...
Do you die?... No...  only if you are in an accident,.. and that accident is serious,... and it occurs in a way that the seatbelt will save you...

Now,.. I do wear a seatbelt in my car,.. but my bike doesn't even have one, and I definitely wouldn't feel safer if it did...

I ridden bikes for 30 years... 26 of those were on bikes with manual petcocks...  and I only ever turn mine off, to remove the gas tank or do carb work...
I have had a stuck float one time in those years,... but it occurred, while I was riding, so a vacuum petcock would not have prevented it.
... and had I not noticed, a vacuum petcock would have hidden the fact from me until I rode again... That's not safe...
(EDIT ...just remembered, I've had a stuck float twice... second time I was parked, and saw the puddle)... there would have been no puddle with a vacuum petcock, but the float would still have been stuck, and would have continued it's leaking once I started up......
I'd much rather see the puddle of gas under my bike while it's parked, than get on it and find out at 60mph on the freeway...

I've bought, fixed, and sold 6 , and maintained 3 more Savages, plus owning one for 5 years, and seen 4 vacuum petcock failures in that time cause, (not prevent), a fuel leak that flooded the engine and airbox with raw fuel...

A "safety feature" that causes more leaks than it prevents, is not a safety feature...  and you will find no official word from Suzuki that it is a safety feature... it is a convenience feature for those that would forget to turn it on or off...  Many people, even mechanics, think it's a safety feature because they don't understand how it operates...
If your float ever sticks, and you have a manual shut-off... turning that off will stop the leak... a vacuum petcock will do this automatically, (as long as it is working properly), and only once you stop, (not while the engine is running)...
If your vacuum petcock ever leaks... there is nothing to turn it off...  You will have to quickly find some pliers, disconnect the vacuum line, find something to block off the hose, then disconnect the fuel line, and do the same,... all the while gas is flowing, possibly over a hot engine...

A vacuum petcock is an accident waiting to happen...
... about a third of members here have experienced a failure...
... another third probably will in the future...
.. and a last third will get lucky, and not have a problem...


Now, you have to ask yourself a question?...
"Do you feel lucky, punk?...  :-?...
Sorry,... didn't mean to call you a punk... it's just too cool of a quote.. ;D ;D ;D...



Serowbot nailed it....

Just think of the OEM petcock as being a great idea that's been poorly executed.  The OEM hardware is notoriously unreliable.

Plus, since I installed the Raptor petcock, tank removal is tons easier than it used to be with the OEM petcock.  Also, my Raptor petcock turns very smoothly and easily.....its tactile feel is much superior to that of the OEM petcock.

JM2C!

Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by Oldfeller on 08/08/11 at 06:53:50



List of Things That Tell You It May Be Raptor Time


1)  Your bike stumbles or acts like it is running out of gas when you are going over 55 mph and then when you get to the pump you can't put in 2 full gallons of gasoline.

2)  Your bike dies on you and you play bloody hell getting it to start again (you can't get any gas from your sick vac petcock no matter what you do to try to get it to start).

3)  When you get a reserve situation and roll the vac petcock toggle to Reserve, the bike continues to stumble for nearly a minute before slowly picking up some power and speed as you struggle to get to a gas station.

4)  You get all sorts of abrupt indications your carburetor is dirty or your jetting suddenly went off (and you haven't changed your exhaust system or air filter system).   Especially applies if SeaFoam, etc has NO EFFECT on your "carburetor issues" whatsoever when you try it.

5)  You smell gasoline either coming from your vac suction line, your airbox or from your oil fill port when you unscrew it (so you can sniff your oil in the sump for the scent of gasoline) because you suspect you have one of the above going on and "it may be Raptor Time".


(actually matey, if you get to #5 and smell gasoline in your oil it is way past Raptor Time already and you may have damaged your bike some already)

Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by Oldfeller on 08/15/11 at 07:35:55


Sticking Floats in the Carb Float Bowl

Solution:  Keep a BIG plastic handled screw driver in your saddle bag until you get your petcock all resolved.


This happened to me twice and it may be happening to you when your vac petcock starves you for gas and your float bowl goes nearly empty (your bike dies in traffic).

Floats only tend to get stuck when they get run to the end of their travel, in your case the petcock starves things until the float bowl just about goes empty and the float itself sticks in the full down (open) position.  Once stuck, the only thing that can free it is a sharp rap on the side of the bowl to jar the float free so it can rise with the incoming gasoline.

So you grab that big screw driver by the blade and use the big plastic handle like a hammer and you sharply rap on the float bowl 2-3 times after you do the petcock test that is shown at the top of Serobots test thread.  There is gas in the bowl again to float the float, so once it is jarred free the float should rise and stop the inflow of gasoline.

Good news is once the petcock stops starving things (or gets replaced with a Raptor if you so choose) the float never sticks again as it is always in the narrow center floating range that it normally operates in.


Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by Oldfeller on 08/25/11 at 15:02:18



Approximate Time Line for Various Petcock Issues


Always under development based on new information, check the revised date down at the bottom of the post for latest revision date.  
Also note the middle items can switch order position for you (the dates do overlap a lot you know)


1)  Vac line getting cracked/holey is the first item in the time line.
(Note:  this time line assumes you fix the vac hose and keep it fixed by yearly replacement or honestly, you will never get past step #1 to get to the rest of the items)
year 5-10

2)  Diaphragm getting partially stiff and failing to flow enough gas at full speeds is the second item in the time line.  
We generally call this "stumbling at highway speeds".
years 7-15

3)  "False reserve" indications start somewhere about here too.  years 7-15

4)  Getting an occasional (rare) stuck float at the ends of float bowl travel (3 raps with the screwdriver handle fixes it) starts somewhere around here too.  These generally happen when the bike "runs out of gas" on the open road when you still have like a half of a tank of gas.
years 7-15

5)  Diaphragm getting so stiff you can't start the scoot sometimes after it dies on you.  years 15-25

6)  Last comes diaphragm pinhole/crack death and the dribble of gasoline down into the air box and the sump.    years 15-25

Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by Ramxes on 03/14/12 at 02:17:36


Hi all , Ramxes here < I just got my 1st Bike,  a 97' LS650 ! (Yep Big Time Newbie)  :P
I've been following tutorials here on the How To's while waiting to get approved to use the forum ...
I bought my LS650 on December 2011, Bike wouldn't start until I cleaned the  carburetor,
I also cleaned the Petcock and did an oil change then I was on the road  8-) for a week   :( ... 

I did my research and follow this Tutorial here , turns out my petcock's
diaphragm is the problem here  , my bike will only now run on PRIME ...
Since the petcock rebuild kit will cost me almost the same as the  :-/ Raptor 660 petcock before buying my Questions are  :

1) The Raptor's Petcock ON /RESERVE position runs the same amount of fuel flow as the stock petcock on the PRIME position?  YES, full flow at all times

2) Now that my Stock Petcock's ON position won't give any fuel flow (works as OFF now)  Is it ok to just run my Bike regularly on Prime ?   NO, you lack a reserve function and will get stranded in traffic when you run dry unexpectedly

3) Has anyone experience bad issues with the Raptor's Petcock?
(Other than over flooding for forgetting to turn to the OFF position)
NOT YET USING NORMAL GASOLINE, and that is on Raptors and Savages by the 10s of thousands over like 8 years now

- Thanks in Advance hope to get to know the crew in this helpful forum.




Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by Ramxes on 04/03/12 at 01:24:36

Finally I received my Raptor Petcock, Spark plugs, and Oil Filters (Tomorrow I will get my brake pads)  :)
http://i137.photobucket.com/albums/q205/ramxes/812a1247.jpg?t=1333440576

While waiting fot my parts I stopped  to Autozone, Pepboys, O'Reilly's to buy all this stuff :  Clamps, 2ft, 1/4" Fuel Line, Fuel Filter, and 5/32" Vacuum Cap (3.96mm)

http://i137.photobucket.com/albums/q205/ramxes/ba318f0b.jpg?t=1333437646

Raptor Petcock Installed with fuel filter :
http://i137.photobucket.com/albums/q205/ramxes/5e0a6c6a.jpg?t=1333440299

This is how the vacuum cap fit perfectly :  
http://i137.photobucket.com/albums/q205/ramxes/065129a8.jpg?t=1333438675

  I Can't wait to Ride it tomorrow (/or later) with a new petcock, new oil change, new spark plug I just finished doing all this work today at 12am (4hrs of work and beer breaks ;D) ... Time to get a rest Zzzz for the big Test ...

Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by heroicseven on 04/05/12 at 08:39:22

 
Where can i get plugs for my vac line like you have there? I went to pep boys but they didnt have them. any ideas.??


All auto stores have them, you simply have to ask the clerk where they keep them as some stores keep them behind the counter.

Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by Ramxes on 04/06/12 at 11:34:26

I bought my vac cap from Pepboys around $3.oo for 2pcs,
Check at Autozone they might also have it : http://www.autozone.com/autozone/accessories/Miscellaneous-Repair-Parts/Vacuum-Cap/_/N-25v0

This is what I got from Pepboys : Vacu-Tite Vacuum Caps (2pcs) 5/32" (3.96mm)
http://i137.photobucket.com/albums/q205/ramxes/c55ac3d9.jpg?t=1333736785

Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by Oldfeller on 04/11/12 at 12:01:39


73727A637F782326170 wrote:
I'm a newbie, first bike, I'm having the same issue with the petcock, the bike runs great with it on prime, in the on position I can barely make it out of my driveway before it shuts off, but it will idle beautifully for hours, I tried throwing some seafoam in the tank to see if that helps, as the bike is a 2003 and has less then 3000 miles on it. Again though the bike still only runs when it is the prime position and sucks gas works then my 6cly car. I took my petcock apart and everything looks like its brand new, the diaphram is good and the hose is good, so i figured i would put it back together and see if running it some more will help but I can't get the little clasp on the outside back on, any tricks for that for those of you that have done the modification to make it manual?


Sadly, I am of the opinion the stock petcock isn't worth messing with.  You can buy a rebuild kit for the vac petcock, but folks find that it doesn't always fix the issues and lastly, for those that do fix it with the rebuild kit, after 3-7 years all the problems simply come back when the new rubber gets old.

So, Raptor once and forget about it -- the Raptor doesn't fail later on.

Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by Serowbot on 04/11/12 at 16:26:13


686961786463383D0C0 wrote:
I havn't been able to ride my bike much the couple times I have with it on prime I've noticed I've barely gotten 30 MPG does the vac petcock make that big of a difference with the MPG? I plan on hopefully using mine to commute to work with each day as it is a 160 mile round trip.

Absolutely none...  Prime vs on, vs reserve, vs Raptor should all be the same mpg's unless something is broken... then, on and reserve could cause fuel starvation...
...or a leaky vac line could cause excessive fuel consumption, but it would so at any petcock setting...

I agree with the last point made -- a leaky vac petcock bike that is trickling gas down the vac line will have poorer gas mileage than the same bike with the Raptor in place (no vac function to be leaking gas).

Still, all said -- your right wrist usage by itself can swing your gas mileage all over the range you have been talking about, and this doesn't have anything to do with petcocks vac or otherwise.

:D

Folks with Raptors like the way their bike runs, so they whack it open more often to feel it GO !!!    Then they see their mileage went down and wonder why.

Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by DNLMusik on 04/16/12 at 05:44:35

 
Might be a silly question, but wouldn't a stock petcock set to prime and a plugged vacuum work just as good as a raptor petcock? Just curious, I realize it's not a good permanent fix!

1 main issue with this idea, you have no reserve function at all -- you are riding along in traffic and you run out of gas and are dead on the spot with no reserve .... on a busy 4 laner this could get right nasty.

Title: Re: Test your Petcock,.. don't just turn it to Pri
Post by Digger on 04/20/13 at 18:54:09


79737170484E54563D0 wrote:
 
Might be a silly question, but wouldn't a stock petcock set to prime and a plugged vacuum work just as good as a raptor petcock? Just curious, I realize it's not a good permanent fix!


I rode mine (see my signature block) like that for a few years with no problems.

I finally swapped the OEM petcock with a Raptor petcock because, after all, my OEM petcock had acted up in the past.....there was no telling what the next failure mode would be (diaphragm material making its way to the float bowl, perhaps?.....It was a known defective component).

You money, your chances....

SuzukiSavage.com » Powered by YaBB 2.2!
YaBB © 2000-2007. All Rights Reserved.