Gas cap leaking gas

I noticed today after I came from my ride that there was gas leaking from the cap of the gas tank. And I could hear a hissing noise from it like there is either air going in or coming out. I was thinking it might be the seal, but I checked it and it looked ok. Who knows though, I do not know what is a good seal or bad seal. And about the noise I hear, could someone tell me what that might be?

Oh and by the way, I guess the tank was painted when I bought it and the rim of the hole for the cap has uneven paint on it. Should it be cleaned and even?

Can I go to any motorcycle shop to buy the seal for the cap or are the seals all different sizes?

All I can give is my personal opinion on this. The hissing is normal. Your tank breather is through the cap.
The same cap is used on the KZ1000MKII and I have over 80,000 miles with that piece of junk. (Cap, not motorcycle).
I bought mine the cap would leak if the tank was more than 3/4 full if I rode hard, so I replaced the seal. Did not help, so I replace the entire cap with a new Kawasaki cap. Did not help. Also replaced the seals on the screws and even sealed the screws themselves to insure leak was from the cap and not the mounts. So since then it's been my contention that the design of this cap is the craps. I just came to the realization to never park the motorcycle in the sun with more than 3/4 tank, never ride hard with more than 3/4 tank. Do these and it will leak every time. Even doing these precautions the cap design just leaks if gas is near it. Even vapors coming out of it will liquify and you'll drip gas down the tank, or stranger yet you'll leak up the tank. I've actually parked on the sidestand and come out to find gas leaking up from the right end of the cap leaking uphill. So I'm all ears too as to whether anyone else finds this cap works without leaks.

Exact same problem with my GPz1100 with a new seal. Poor design.

KZ1000CSRman wrote:

I noticed today after I came from my ride that there was gas leaking from the cap of the gas tank. And I could hear a hissing noise from it like there is either air going in or coming out. I was thinking it might be the seal, but I checked it and it looked ok. Who knows though, I do not know what is a good seal or bad seal. And about the noise I hear, could someone tell me what that might be?

Oh and by the way, I guess the tank was painted when I bought it and the rim of the hole for the cap has uneven paint on it. Should it be cleaned and even?

Can I go to any motorcycle shop to buy the seal for the cap or are the seals all different sizes?

Click here > Tank cap seal from Z1E

Good Fortune!

I would clean the paint off the lip of the opening and replace the rubber seal. That's very cheap and easy, and there's a 75% chance it will fix your problem. Ed

You guys have apparently never had experience with this here cap.:laugh: If a seal fixes it, or cleaning off paint fragments does you're much luckier than me.

My mk2 cap doesn't leak. It has a new seal and screw gaskets.

If your cap is the same as my 82 1000LTD and the tank has been repainted as mine was. There are 2 orings under the bracket (one for each screw) that holds the cap assembly on.
The guy who painted my tank left the orings out when he put the cap assembly back on. I replaced the seal first and it didnt help at all but the orings took care of the problem altogether.
Tom

kawasaki.com says the 0-rings are still active parts available from dealerships.

Good Fortune!

[Click on image to enhance view.]

EDIT -- see pgboyd's later post that 92055 is the 0-ring.

I changed the seal and the O rings and it still leaks. Worst yet, it also seeps threw the key hole also.

my 74 's gas cap leaks the same so i only fill it to about 3/4 full and fuel up more often not a problem for me. but i tend to ignore the little things

timebomb33 wrote:

my 74 's gas cap leaks the same so i only fill it to about 3/4 full and fuel up more often not a problem for me. but i tend to ignore the little things

Caused a double-take from my aging memory bank when all the big Harleys were "74's" :laugh:

Good Fortune!