Petcock

[2strokedGT]

What is the size or diameter of the hose for the petcock?
Reason being I have given up on the old petcock as it leaks internally as the vacuum does not shut off the gas anymore.I plan on buying a new Suzuki OEM one but I see they only sell the newer ones with
the one fuel barb outlet my current one has the 3 barb outlet as its a 72' motor so my plan is to buy a 4 way splitter and split the one into the 3 hoses for all my carbs once I figure out the hose size.
Any help appreciated

[oldjapanesebikes]

Volker sells rebuild kits and also rebuilt fuelcocks which are very good - depending on the exchange rates they can be expensive but are worth looking at. Take a look at this link.

[2strokedGT]

I actually rebuilt the whole thing last season with a kit and it didn't seem to help
maybe the diaphragm is shot if I understand correctly that part is not sold anymore.
But back to my main question..what are the fuel line hose size or diameter?
Tried a 5/16 and it doesn't fit and searched all over and can't find a simple answer.
Thanks

[oldjapanesebikes]

Volker sells the diaphrams also, as well full reburbished units on an exchange basis - and if yours isn't listed, he will build to spec. Good guy !

But moving on - based on the part number for the later single outlet fuelcock (09343-07020 - still available from Suzuki) it appears to be 7mm. Hope that helps !

[jeff g]

You can try Jess Freeby at jessbikes.com. He sells Kawi triple parts, but the petcock for the early GT380 should be the same as the H1/H2 petcock...I'm pretty sure the internals are the same as the GT550 and, even though the mounting is different from the Kawi, early GT550 petcock parts are identical to the Kawi parts.

Jess has the complete kits with diaphragm, and he might sell the little diaphragm o-ring separately as that is the part you probably need...that is what actually allows the diaphragm to shut off the fuel. Jess is a good guy to deal with.

Jeff

[oldjapanesebikes]

I'm pretty sure the internals are the same as the GT550 and, even though the mounting is different from the Kawi, early GT550 petcock parts are identical to the Kawi parts

I'd double check the pintle lengths on the diaphrams before buying - I recall H2Rick and I measured a few some years ago and some (I can't recall which) were too short. I also ran into a different problem with an early T500 and the later ones - the shoulder on the pintle prevented the o-ring from seating properly. Just something to be aware of.

[Coyote]

The diaphragm has nothing to do with fuel shutoff. Shutoff is a spring behind the pintle, a good o-ring and a smooth seat. The vacuum operates the diaphragm function which over rides the spring tension , pulling the o-ring off it's seat and allowing fuel to flow. When the vacuum stops, the spring takes over and pushes the o-ring back on it's seat - shutting off the fuel.
A bad diaphragm generally results in no fuel flowing because it can't over ride the spring tension and let the fuel out. 99 times out of 100, fuel not shutting off is due to a bad o-ring. That tiny o-ring is the key to the whole petcock operation. The trouble with rebuild kits is most all do not provide that o-ring. No one sells the o-ring by itself either. The only kit I have seen that includes the all important o-ring is available at HVC Cycle. http://www.hvccycle.net/petcock-reseal-kits/" onclick="window.open(this.href);return false;

[2strokedGT]

Great info on the petcock diaphragms I also heard about the Kawi H2but would work but it seems the prices are cutting close to what a brand new Suzuki OEM would cost.

Coyote I actually did get the HVC kit with the O ring and installed but your excellent description on the inner workings of the petcock gives me the idea that I will probably take it apart and see if I can fix it if I remember correctly when I put it back together I stretched the spring out a little and its slightly bent at an angle so that may be the problem right there.I have a spare 3 barb petcock that I can get a spring so i'll give that a try along with cleaning it up.

[jeff g]

Jess' kit includes the o-ring also. Prices might be close, but that diaphragm is what drives the cost. When it was still available, the diaphragm by itself was over $80.00 through Kaw. Suzuki never offered it as a separate part.

It's nice that the Kawi parts can be ordered through Suzuki. Kawi oil tank sight glasses are also available through Suzuki.

[2strokedGT]

Well I pulled off the petcock swapped the spring with my $10 spare ebay petcock and also decided to swap diaphragms and the plunger piece also before I snapped it back together along with the newer HVC O ring
Filled the tank with gas and not one drop came out the fuel barbs when set at on Success!
Took it for a half hour drive and its running flawlessly
The internet is truly a wonder a few words of wisdom from the knowledgeable folks on this board and the problem is solved saving myself the cost of a new petcock.

[Coyote]

If your spring was pushing the plunger at an angle, that was probably the whole problem. It's so nice when the petcock is working right. You can take the tank off anytime and not make a mess with fuel. It's a simple yet ingenious device and a real PITA when they go bad. It's nice to know that HVC is providing the correct o-ring in their kit. Glad I could help!