1979 gs1000L petcock problems.

[micxster]

I have a 1979 gs1000l that I have owned for 5 yrs. Its been a good bike. Recently however, it has been almost impossible to start. Once it starts , it runs great, but after it has sit for a few days, it can take a half hour to fire over. I have traced the problem to the fuel petcock diaghram. After I removed it and held it up to sunlight, I could see that there where a couple of pinholes.
I have found a few diaghpram repair kits online , and bought one that said it covered " all 79-81" gs 1000 bikes. It doesnt fit, the plunger on the diaghram is too big. It would fit my 1980 gs1000 "G" but not the '' L" .
Now for my question, is the '' L'' series of gs 1000 an oddball ? Ive noticed no online petcock/ diaghpram supplier specifically mentions the "L'' series in their application charts except for one, and it mentioned it exclusively for that model ONLY. Of course they were sold out too.
Any ideas on how I can fix the petcock and get the big suzie up and going again? Thanks

 

[Larry D]

Welcome !!!

I'm not personally familiar with rebuild kits. The one that I had, that was bad, I just bought a complete new one.

The difficult starting may be due to the valves needing adjusted, it's a very common problem. When's the last time you adjusted the valves ?

 

[sschering]

Ive noticed no online petcock/ diaghpram supplier specifically mentions the "L'' series in their application charts except for one, and it mentioned it exclusively for that model ONLY. Of course they were sold out too.
Any ideas on how I can fix the petcock and get the big suzie up and going again? Thanks

Are you are talking about the Carb Kits Capital pecock kit?

http://www.carbkitscapital.com/carb_kit_list_model.php?make=Suzuki&model=GS1000

Part #20-0054

I used it on my 79 L.. The PO had put in the wrong kit and it wouldn't seal.. Same issue.. the plunger was to big.
The kit I got from CCC fit and functions perfectly.

I can't remember off hand who the manufacturer of the kit was but I have the tag at home.

 

[micxster]

The bike sounds great after it starts. No valve chatter, and when i force gas into the carbs it will start right up and stay running. I would have suspected other problems if it werent for the holes in the diapghram.
I havent adjusted the valves as of yet. The donor engine I used came off a bike that had around 11k miles.
I just figured I would try to eliminate the diapram as a possibilitiy before tearing into the engine.

 

[BassCliff]

Greetings and Salutations!!

Greetings and Salutations!!

Hi Mr. micxster,

You'll want Suzuki part# 44300-49172. The superseded part#'s are 44300-49170 and 44300-49171. This part number is also used on the 1980 GS550T and ET. OEM petcocks are a little pricey but you have to replace it only once every 20 years or so. You could also use a "universal" part like a Pingel. You might need an adapter plate. Start at Z1Enterprises.com. There are more vendors links below. Let me share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

 

[micxster]

"Are you are talking about the Carb Kits Capital pecock kit?"
------------------------------------------------------------------------
Yes, I went to there site, but was leery when they didnt have a contact phone # and they were out.
Ive got a 1980 gs1000 g parts bike. The petcock doesnt even have the same bolt pattern , nor same diaphram.
I went on ebay but couldnt find ANY specifically for a 1979 gs1000L.

Do you have a phone number or url for the place that you got yours. Suzuki dealership wants $112 for a new "petcock assembly". I jst want the diaghram, every thing else works and seals up okay. Thanks.

 

[micxster]

@ Basscliff- Thanks. I will check out the info. This is a really impressive website. I have owned 5 suzuki gs bikes (in varying states of dis repair) and really like the style and power.

 

[Nessism]

I havent adjusted the valves as of yet. The donor engine I used came off a bike that had around 11k miles.
I just figured I would try to eliminate the diapram as a possibilitiy before tearing into the engine.

Why would you ride the bike without knowing the condition of the valves? By the time the bike starts showing functional problems due to tight valves it will be too late (burned valves).

 

[sachsaca]

I started to buy a rebuild kit from Z1, it isn't thr ight one though, be careful I think the L is an odd ball. Hit up Z1 and I bet they can get you the right thing or take th epart number and go that way by a dealer. You might pay a little more but isn't it worth being able to get it right.

 

[micxster]

Ed, You have a point there. I may adjust the valves soon, but I wanted to start with the simplest and most obvious problem first. Diaghram with pinholes, then move on to some other problem area. Thanks for your advice.

 

[sschering]

I ordered it through the web page. Paid by paypal and it showed up in under a week.

You could try sending them an Email so see if they will get any more in stock.
carbkitcapital@hotmail.com

The hotmail address is a concern but he they did deliver.

The kit I got was made by Tour Max.. I can't find anyone else selling Tour Max parts except a few old stock bits on ebay..

 

[Dave8338]

Ed, You have a point there. I may adjust the valves soon, but I wanted to start with the simplest and most obvious problem first. Diaghram with pinholes, then move on to some other problem area. Thanks for your advice.

Rip the head off, split the cases and rebuild the thing!

What are you waiting for??




Welcome to the GSR. GREATbunch of peeps! :dancing:

 

[Nessism]

Ed, You have a point there. I may adjust the valves soon, but I wanted to start with the simplest and most obvious problem first. Diaghram with pinholes, then move on to some other problem area. Thanks for your advice.

Guess I'm a freak, because I wouldn't even attempt to put a bike on the road without checking the valves first. I don't care how good, or bad, it's running. The maintenance gets done first thing before the bike leaves the garage.

 

[sschering]

I just got a Email back from CarbKitsCapital

It's back in stock
http://www.carbkitscapital.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=C&Product_Code=20-0054

 

[Guest]

The bike sounds great after it starts. No valve chatter, and when i force gas into the carbs it will start right up and stay running. I would have suspected other problems if it werent for the holes in the diapghram.
I havent adjusted the valves as of yet. The donor engine I used came off a bike that had around 11k miles.
I just figured I would try to eliminate the diapram as a possibilitiy before tearing into the engine.

I would think it would run in "Pri," have you tried it? Rebuilding petcocks is a tricky thing. I had three that leaked. One was just an outside O ring under the lever. The second I replaced the diaphram and it still leaked when turned off, I worked the diaphram seat and eventually it stopped leaking, I just don't trust it now, and the 3rd, I reworked extensively, it
still leaks when shut off, badly too, but there's a check valve in the petcock that goes to the the vacuum line and I think it's bad, so no matter what I do I haven't been able to get it to stop leaking. If those holes in your diaphram are small enough I wouldn't think it would stop the vacuum from opening the diaphram allowing fuel to reach the engine. Have you tried it without the gas cap? sometimes those vented caps plug up, but it should start up and run initially until the vacuum building up in the tank prevents the fuel from reaching the petcock, check your vacuum line for kinks, holes, and loose connections.
You could check your petcock, first you'd have lower the amount of fuel in your tank to the point none reaches the petcock by siphoning it or if low enough raising your tank in the back. If you don't think your petcock will leak then just remove your fuel line and connect another hose, preferable something you can see through to the fuel line and something the flowing fuel can go into, (a gas can). Attach another hose to the vacuum line at the petcock. Once done add enough fuel to the tank to be able to check it in the run and reserve position. But first select "Pri" and fuel should run easily, then switch to "Run" and fuel should shut off until you suck on the vacuum line, and then do the same with reserve. I would do that before I did anything else.

 

[sschering]

I would think it would run in "Pri," have you tried it? Rebuilding petcocks is a tricky thing. I had three that leaked. One was just an outside O ring under the lever. The second I replaced the diaphram and it still leaked when turned off, I worked the diaphram seat and eventually it stopped leaking, I just don't trust it now, and the 3rd, I reworked extensively, it
still leaks when shut off, badly too, but there's a check valve in the petcock that goes to the the vacuum line and I think it's bad, so no matter what I do I haven't been able to get it to stop leaking.

The 79 Petcock has no prime setting.. Just run and reserve..
When the bowls are dry getting it primed is a big PIA.. suck on the vac line or crank till the cows come home.

That check valve is on the air side of the diaphragm cover.. It's real job is preventing a diaphragm rupture in case of a backfire.
If it's bad and leaking air the petcock will never open.
Fuel out the vac line or check valve vent would be leaking from the diaphragm.

When I did my petcock I just striped it down and threw it in the dip can for 10 min (enviro safe dip from NAPA that won't attack rubber but will swell the crap out of it if left for days). Inspected the surfaces, assembled , tested check valve and gave it a leak test on the tank..

I guess the other odd thing with the 79 is the petcock to tank seal is just an O ring that goes around the outside the bolt holes.
You need gaskets under the screw heads or it will leak there.
The kit didn't come with any so I made my own from a roll of gasket material I had laying around.

 

[Guest]

The 79 Petcock has no prime setting.. Just run and reserve..
When the bowls are dry getting it primed is a big PIA.. suck on the vac line or crank till the cows come home.

That check valve is on the air side of the diaphragm cover.. It's real job is preventing a diaphragm rupture in case of a backfire.
If it's bad and leaking air the petcock will never open.
Fuel out the vac line or check valve vent would be leaking from the diaphragm.

When I did my petcock I just striped it down and threw it in the dip can for 10 min (enviro safe dip from NAPA that won't attack rubber but will swell the crap out of it if left for days). Inspected the surfaces, assembled , tested check valve and gave it a leak test on the tank..

I guess the other odd thing with the 79 is the petcock to tank seal is just an O ring that goes around the outside the bolt holes.
You need gaskets under the screw heads or it will leak there.
The kit didn't come with any so I made my own from a roll of gasket material I had laying around.

It's unfortunate that the '79 GS1000L has a petcock that doesn't have a prime position. That makes troubleshooting this petcock harder. I don't believe I've even seen one anywhere for sale. Like you said if the check valve is bad the diaphram which opens from vacuum and allows fuel to the carbs may not open at all. True there's a gasket type of washer under the two 10mm bolts/screws securing the petcock to the tank. The part number for those is 09168-06023 and they're called "washer, oil gallery exhaust" @$1.12 each at Boulevard Suzuki.