1980 GS250T | Petcock Gasket Help

[Guest]

Hi all, I'm looking for the bottom most item in the picture for a 1980 GS250T. This doesn't show up on the part drawings from the suppliers and it doesn't seem to come in the rebuild kits (at least for that bike). Am I looking in the wrong locations? Is this a general item that fits most petcocks? It seems like I have to buy an entirely new petcock, but that's not something I'd want to do unless necessary.
18-4344-pu-gs450-gs550-gs750-gsx-r-gs1100-petcock-rebuild-kit-18-4344.jpg

TIA -- Chris

[hugo151]

That's the main part of the rebuild kit, if that ain't in it, forget it ! What are your symptoms ? Leaks ? Has it got a prime screw ? If it has, there are 2 little "O" rings on it which fuel can leak past, they,ll be 30 odd years old & they don,t come in any rebuild kit. Try gsx 250 E or Gs 450

[harth]

The crankcase has been filled with gasoline. It happened twice and I don't think it's the floats getting stuck. I'm going to disassemble the petcock again and look for those o-rings. Last time I looked, this diaphragm thing was pretty worn and I figured gas was getting past that.

[JJ]

Rebuild kits have a low success rate. Do yourself a big favor and spring for a new OEM petcock. You will be good to go for another 30 years or so.

[harth]

Rebuild kits have a low success rate. Do yourself a big favor and spring for a new OEM petcock. You will be good to go for another 30 years or so.

Understood. I just did some research, but not getting a full answer yet... I've heard big hype about the Raptor petcocks on eBay. Are you familiar? It looks like they have the same mounting holes and have a good report of limiting those issues of the original type.

[JTGS850GL]

Those "original types" lasted 30+ years. I'd bet that none of the aftermarket petcocks have as good a track record. I'd consider buying a new petcock "necessary" .

[harth]

Those "original types" lasted 30+ years. I'd bet that none of the aftermarket petcocks have as good a track record. I'd consider buying a new petcock "necessary" .

It was more of a design question. I wouldn't disagree that the originals were probably built somewhat better. From what I understand when switching to a Raptor it's replacing the vacuum feed petcock to a gravity feed petcock. With the ability to turn it on and off, it seems it would eliminate the error of either fuel constantly priming into the carbs or a lack there of. Either case, I will order a new petcock and replace fuel lines. From my knowledge I don't believe they have be replaced.

[gustovh]

If the valve body surface that the O ring on the diaphragm seats against is not smooth, the valve will leak. I had to make a mandrel out of a piece of aluminum round stock, matching the angle of the seat, and polished with brasso until a good seating surface was achieved, changed the O ring on the diaphragm. Hasn't leaked since.

V

[harth]

If the valve body surface that the O ring on the diaphragm seats against is not smooth, the valve will leak. I had to make a mandrel out of a piece of aluminum round stock, matching the angle of the seat, and polished with brasso until a good seating surface was achieved, changed the O ring on the diaphragm. Hasn't leaked since.

V

Good to note, I'll take a look at that.

[JTGS850GL]

It was more of a design question. I wouldn't disagree that the originals were probably built somewhat better. From what I understand when switching to a Raptor it's replacing the vacuum feed petcock to a gravity feed petcock. With the ability to turn it on and off, it seems it would eliminate the error of either fuel constantly priming into the carbs or a lack there of. Either case, I will order a new petcock and replace fuel lines. From my knowledge I don't believe they have be replaced.

Go with the manual petcock, but make absolutely sure you turn it off EVERY TIME the engine is not running or you can risk filling the engine with fuel.

By the way, the stock petcock is gravity feed as well. It just has a vacuum actuator safety feature that's normally quite reliable.