New to GS - Fuel leak problem

[blenin]

Hello All.
I just purchased a 1981 GS450 for my wife. I am not very knowledgable when it comes to wrenching bikes so please excuse my ignorance! When picking up the bike last night, I noticed that the petcock was in the prime position & questioned the seller. He said he never noticed it (he had the bike for a month) and had always ridden like that! I got it home and switcxhed it to "on". I noticed that there is a very slow gas leak that appears to be coming from the petcock. Could this have been caused by him riding it on prime & leaving it that way twenty four seven? Any suggestions?
Thank you - Paul

[gspaul]

Hi Paul, it could be the po found the tap would not leak in the pime position!
Rebuild kit's are still around for these tap's, you don't want to leave it on prime, if you get a bit of dirt in one of the float needles you can end up with a crankcase full of fuel( not nice)
It's easy to pull apart, so have a look, see what you find.

[gsBert]

hey paul, yeah paul is right on that. if you want a cheap fix, leave it on prime and pinch the fuel line with a clamp (some are available for just that purpose at any bike shop)
my guess is that the diaphragm in the petcock is broken.

where does it leak from in the petcock? (fuel line or vacuum line, or just the casing?). sometimes the diaphragm that controls the vacuum switch for the run position breaks and that causes gas to leak into the vacuum hose or out of the petcock. that i'm guessing is exactly what's happening to you this does not happen in the prime position. in this case, get a new petcock or do the clamp trick i described above.
if your float valves don't leak you should be fine, but if they ever do, the prime position will empty your gastank, and your carbs will overflow. you might come back to your bike to find it sitting in a pool of fuel. (that's why i'd clamp the fuel line shut when not riding the bike, just make sure to unclamp before starting it)

[blenin]

Thanks guys. I'm not sure where the fuel is coming from, it appears to be the casing on the petcock itself. The leak is acutally pretty minor, just a couple of drops seem to dripping & then it stops. I checked this morning and it appears to be dry. Go figure. I'm going to check into the clamp. I'll have to post a good picture of her pink & purple GS450 for all to see!