GT750 Petcock: repair or replace?

[MikeH1A]

I've just started pulling bits off the GT to begin the big spruce up. However, I did go for a ride yesterday and was very impressed with the acceleration of the big girl - not as lumpy as they look

As I took the carbs off, it became very clear that the vacuum aspect of the petcock is not working. Petrol just kept coming out of all the lines. Is it possible to rectify this or do I need another petcock?

Thanks, Mike

[advant63]

the diaphragm is probably ok. just stuck, or fuel would be coming out the vacuum spigot as well. i vote for a rebuild. suzuki petcocks are a bit expensive and not correct (black). thailand petcocks are total garbage.

[oldjapanesebikes]

For the GT750J/K the internals of the pet cock diaphragms are the same as those used on Kawasaki '69 through '72 H1's and those bits are still available from your Kwack dealer.

[MikeH1A]

Thanks for that. Think I'll pull her apart and see what looks not so flash. Will check against the parts diagram - I've learned that P.O.'s don't always put everything back

[Coyote]

Probably all you need to replace is o-ring #26. Diaphragms tend to stick to adjacent parts but can be easily separated with a DULL razor blade.

[Rustygt550]

Thanks great info!! Do you have the part number for part #24

[oldjapanesebikes]

Just take a look at the fiches here for part numbers. Availability will vary by country so you may have to do some searching to find a dealer than can supply what you need.

[markj]

If the seat where the #26 o ring sits is corroded you can clean it with a q-tip and some polish so it doesn't have that infernal "slow drip".

[Coyote]

Depends on how deep the corrosion is. I cleaned up mine with a pencil eraser and some rouge. Lightly clamp the body in a vice with the seal surface facing up. Roughly shape rhe eraser to the taper. Apply some compound to the eraser and spin the pencil with your palms.
Mine does not leak which makes removing the tank a breeze.

[tz375]

Is that small O ring still available? I have two petcocks with small hard O rings that broke up when I tried to pry them off.

Mine is a 74

[oldjapanesebikes]

Is that small O ring still available? I have two petcocks with small hard O rings that broke up when I tried to pry them off.

I went into a seals and services outfit here in town that Uncle Rick suggested, and matched up some viton o-rings that seem to work fine. HVC offers the small o-ring also, but only as a part of a kit.

[H2RICK]

Another good refurbishing device for the pintle seat is an unused chopstick from your favourite Oriental takeout place. A little work with a sharp knife so the chopstick end matches the taper of the pintle seat
and you can whirl it back and forth between your palms to polish the seat just like lapping a valve with a valve seating stick.
If the seat has visible corrosion pockets in it, you might want to try the same trick with a little extra fine valve lapping compound on the chopstick......but don't overdo it. Five or six rotations of the chopstick and then wipe the seat clean and check it. Repeat as necessary.

[tz375]

Is that small O ring still available? I have two petcocks with small hard O rings that broke up when I tried to pry them off.

I went into a seals and services outfit here in town that Uncle Rick suggested, and matched up some viton o-rings that seem to work fine. HVC offers the small o-ring also, but only as a part of a kit.

I have an HVC set and that O ring is a couple of sizes too large for4 some reason. I'll try the local auto store in the morning

[Jughead]

If you can't find one of the regular Black O-rings that you need see if they sell Green Air Conditioning Orings.They come in Strange Sizes and are Gas resistant.

[Suzsmokeyallan]

Jug you wont find an A/C line o-ring in that size, not even a high side o-ring is that small. You would have to size it at an o-ring store or get an HVC kit.