Bike Leaking Gas while its off! Answer!

This is my answer to my own question for those of you who may have this problem. I searched for the answer in these forums and only found one vague mention eluding to the fix.

My '82 550c LTD was leaking gas when it was off out of the carb overflow tubes. I rebuilt the carbs and adjusted the floats like 5 times (i've gotten wuite good at it). So what is the answer?

Its in the pitcock! Its easy to take apart. Find the cirular O ring with 4 holes in it. I'll bet it doesn't look so good! replace it! there you go ! gas stops leaking! I hope this helps sombody! Life is a lesson.

Best Regards!
KZs Rock

hey thanks, i think i may have this same problem!

I will look at this first!

:whistle:

Carbs give me nightmares ... I can take them apart in about 10 minutes and they still make my blood boil haha

I've just had this problem start over the last couple days.
I'll start where you say and move on to the carbs if I can't solve it.
Are replacements for the o-rings in the petcock hard to find or can I find something standard that will work?
I have a 1980 KZ 440

Z1E (probably) has everything you need.. I got a petcock kit from them for my 550, and it's working perfectly now..

Earlier I had to nearly drain the tank and have it tipped up so it wouldn't leak while I had it off the bike, but now I can leave it full and just put it down and it doesn't leak a drop after changing the rubber bits out.

That includes the vacuum diaphragm, and 2 o-rings..big one around the mounting plate, and small one under the lever (with the 4 (5?) holes in it).

www.z1enterprises.com/

Hi,

Had the same problem and went to the same process.

Was leaking even when I rebuilt the petcock but stop once I extend a little bit more the spring inside the petcock to give more pressure.

Check your oil level because on the GPZ750, the exess of gas was going in the motor base.

Joce

Oh yeah..that's a good point too, I extended the spring as well. You have to pull it a fair bit too, to make sure you get a decent amount of pressure.

Very good point..

Fuel should not drizzle from overflow nipples even if petcock left open.

Fuel enters the float bowl through the float needle seat. The float needle serves as the seat doorway. When fuel reaches proper level in the bowl, the float rises and presses the pointed float needle tip into the seat (closing the door) which supposedly blocks any more fuel from entering the bowl.

A poor seal between the float needle seat and pointed tip of the float needle is like a crack in the doorway which continues letting fuel into the float bowl, which then overflows.

Some float needles have a rubber point while others have solid metal tips.

The closure fit between float needle seat and float needle tip must be perfect to completely seal. That's one reason it's best to replace them in pairs, and not to mix and match during reassembly.

A grain of grit in the doorway can result in a steady stream of fuel from the overflows.

Some crud might be displaced by using Seafoam or similar product mixed into the fuel.

Turning off a properly operating petcock stops fuel from reaching the doorway, but does not repair the crack.

If float level is adjusted properly, and floats are floating, and fuel drizzles from float bowl overflows, it's a safe bet that the float needles are not properly seating inside the float needle seats.

That's right. If everything is right in the carbs they will never leak even with the petcock set to prime for an entire year. The big problem I used to have with petcocks is the darn vacuum diaphram would stick in the on position. This caused no problem as my carbs never leak, however you get a real nice surprise when you try to remove the tank when gas gushes out all over.