Leaking VM carb bowls your thoughts

[jimfj]

77 GS 550. 12,000 miles.

Overall good condition bike.
I have a very very small leak coming from the float bowl to carb body area. (as far as I can tell)

The problem shows itself when bike is parked on side stand.

Carbs have been disasembled and cleaned and new Cycle O rings kit installed. Carbs were fairly decent to start with. Float levels were checked and all were within the 24mm +/- spec.

After searching it seems this is a somewhat common problem with the older VM carbs. However I cant believe that it can't be cured.

I also checked the overflow tubes with a magnifying glass and they seem to be fine. I have seen others and know the difference.

Another area of concern seems to be the needles and seats. I believe they are fine....they look like new and the spring seems to be strong.

On the centerstand they do not weep, but, gas and oil leaks just flat **** me off and the bike is stored indoors and i really don't want to deal with the fumes.

Any help is appreciated.

Jim

 

[shinzon1]

I had similar situation when i put new bowl gaskets on mine. I pulled them back off and re-tightened the screws and haven't had a problem since. It doesn't take very much space for gas to find a way out. Just try tightening your bowl screws again. should fix it.

 

[tkent02]

If your petcock wasn't flowing some fuel when it shouldn't be there would be no fuel in the bowls high enough for any leakage. Replace the petcock.

Messing with the carbs is fixing the symptom, not the problem.

 

[tom203]

If it doesn't weep on centerstand, your petcock might be OK (but this would be a good time to check petcock operation). Are all carbs weeping? I'd suspect the float bowl gasket on one carb, but not all four.

 

[hampshirehog]

The float bowl gasket is not designed to hold back fuel. rather it just holds back slop - fuel level going high at the back of the carb on heavy acceleration, high at the front on braking.

If your float height is correct it's a problem with your fuel tap.

 

[shinzon1]

my petcock was fine. just had one bowl gasket that apparently hadn't sealed all the way.

 

[gssuzukixxx]

Even if you have the float heights set the same you may still have a high fuel level in that carb. The only way to tell for sure is with the clear plastic fuel level checker.

The fact that it only seaps gas when on the side stand makes me think this too.

Brian

 

[jimfj]

I forgot to add,

petcock works as it should. that was the first thing I checked. No whatsoever on reserve or on. Pours on prime.

I took the rack off and sparingly used gasket sealer on the bowl mating surfaces after making sure they were spotlessly clean. This has cut the drips down just not stopped it completely. On centerstand for 24 hours and no gas film on bowls.

Put the bike on the sidestand and will start to slowely drip. AAARRRGH

 

[verde]

I took the rack off and sparingly used gasket sealer on the bowl mating surfaces after making sure they were spotlessly clean. This has cut the drips down just not stopped it completely. On centerstand for 24 hours and no gas film on bowls.

Most gasket maker/sealer is not fuel resistant.

 

[AJ]

Most gasket maker/sealer is not fuel resistant.

Ditto - if you used RTV silicone, RTV does not resist gasoline.

 

[btbarb]

77 GS 550. 12,000 miles.

Overall good condition bike.
I have a very very small leak coming from the float bowl to carb body area. (as far as I can tell)

The problem shows itself when bike is parked on side stand.

Carbs have been disasembled and cleaned and new Cycle O rings kit installed. Carbs were fairly decent to start with. Float levels were checked and all were within the 24mm +/- spec.

After searching it seems this is a somewhat common problem with the older VM carbs. However I cant believe that it can't be cured.

I also checked the overflow tubes with a magnifying glass and they seem to be fine. I have seen others and know the difference.

Another area of concern seems to be the needles and seats. I believe they are fine....they look like new and the spring seems to be strong.

On the centerstand they do not weep, but, gas and oil leaks just flat **** me off and the bike is stored indoors and i really don't want to deal with the fumes.

Any help is appreciated.

Jim

+1 on what Brian said about the clear tube float level check.

I've read a lot about this subject here too, but there's not much mention about the fuel in your fuel line and connectors that is trapped after you park, it will try to flow to #1 and #2 when on the stand. It may take hours, but it is probably making it past the float valve needles. If your float levels are at the high end, this may be all it takes to raise the float level to the gasket. If you have clear fuel line, you can see the fuel line will be full when you park and then check the next day and the fuel line could be empty. If the fuel line stays full after a whole night, your float valve needles are perfect or your petcock is leaking. Seems if you pull the fuel line on the petcock nipple and put a rag under it and wait a night, you can rule out if the petcock is dribble leaking on you.

 

[Guest]

Since the fuel is not coming out of the overflow tubes, and it only does it on the sidestand, sounds like it's leaking from the mating surfaces from the float bowl to carb body, where the fuel in the bowl is no longer level but shifted to one side, perhaps high enough to reach the mating area of the carb bowl and body.
If it were a faulty petcock, I would think he'd be leaking from his carb overflow tubes also.

 

[jimfj]

I can confirm that the leaking is coming from the bowl/carb body, not the overflow.

If the gasket sealer isnt fuel proof what does everyone suggest to seal the leak? I have used this stuff, with great results, on both fuel and brake fluid leaks on other projects.

http://www.totalmotorcycle.com/reviews/SealAllGlueReview.htm

My concern with using this is that it hardens up pretty well. Not sure if the bowls would come off easily if I did.

If I replace all the bowl gaskets, whose does everyone reccomend? Are Z1 needles and seats good or do we reccomend someone elses?

 

[Guest]

As for parts, Boulevard Suzuki,
Depending on which carb set you have for your 550.
http://www.boulevardsuzuki.com/fich...y=Motorcycles&make=SUZUKI&year=1977&fveh=2106

or..........

http://www.boulevardsuzuki.com/fich...y=Motorcycles&make=SUZUKI&year=1977&fveh=2106

 

[Big T]

I wouldn't use that glue -if you have to go that far, you're just masking the real problem

Some soft permatex like 80938 Tack and Seal is all I'd use for the gaskets

No nicks or unevenness in the bowl mating surface?

Which carb are we talking about here? #1?

What gaskets did you use?