fuel cap spring collapse!

I thought I could smell fuel somehwere on the rex everytime I filled it right up to the top???? I really didn't take too much notice, till it started splashing out all over me on the ride yesterday.....mmmmm!!!!

Knowing some common issues, I just pulled it all apart to see if they may be the culprits. 1st thing I checked was the vent and then the drain. It vents perfectly when enough pressure builds up and the drain works fine. (I poured some fuel down just to be sure and it popped right out where it should behind the swingarm pivot bolt, I then blew it out with the air comp to make triply sure!!!) So it's neither of those I wouldn't think.

I checked the condition of the rubber, as the bike had sat for two years I figured it might be perished. But no, it doesn't have a crack, split or perish mark anywhere and actually is in better nick than the one on my ZX9, which doesn't leak. While there I had a good look. It appeared as thought the springs which force the rubber seal down onto the top lip of the filler hole, had lost spring tension. So, in the absence of a replacement part on Easter Monday, I pulled the cap apart, removed the springs and elongated them using the highly technically advanced needle nose pliers!!!! I stretched them out about 30% more than they were and refitted the cap to the tank. It closes still, if firmly. So we will see on the next ride if that has solved the issue??? Anyone else had spring tension issues on Kawasaki caps???

not spring tension issues, but the fuel cap on the mighty 6fiddy leaks like a sieve if the fuel is closer than 2" to the filler neck.........it pisses out all over the place........the rubber seal is fucked. Time for a new one...

Yep i have issues with the cap on the z,everytime you really open it up or go over a big bump the cap pops open.But i suppose at 32 years old its allowed to

not spring tension issues, but the fuel cap on the mighty 6fiddy leaks like a sieve if the fuel is closer than 2" to the filler neck.........it pisses out all over the place........the rubber seal is fucked. Time for a new one...

Yeah, mine's the same....but I've put a new seal on it so hopefully it'll be right when it's going again

HM's ZZR does that. Unfortunately, it was me riding it the first time it did it ... all over my fresh paint job.
If we fuel it on the sidestand it doesn't do it so we haven't really tried to find out what is actually causing it, other than it seems to have an air bubble higher than the filler cap and when it pressurises like in the hot sun, the only way out is through the cap. I am also guessing that might have something to do with the filler position being changed on the next model.

7..or 8 Kwakas in the past 15 or 25 years
never had a fuel cap issue....

Marty
how can screw a fuel cap....??



cheers

Smitty

Yeh I can sorta relate to your problem Marty, not the spring collapse.... but have been riding and wondered why I could smell petrol? look down and sure enough petrol had come out the from the cap. The petrol appears to be coming thru the keyhole in the cap, still not sure why tbh
Admitedly I have overfilled it a couple of times, but I don't think that's the reason. Something to do with the cap I think?
I also have a problem with the key cover on the cap, sometimes it gets stuck and I struggle to open it - I thought this was because I lie on the tank on long trips and maybe I've stuffed it as a result. Again its something that occurs intermitently. Any idea's?

Yeh I can sorta relate to your problem Marty, not the spring collapse.... but have been riding and wondered why I could smell petrol? look down and sure enough petrol had come out the from the cap. The petrol appears to be coming thru the keyhole in the cap, still not sure why tbh
Admitedly I have overfilled it a couple of times, but I don't think that's the reason. Something to do with the cap I think?
I also have a problem with the key cover on the cap, sometimes it gets stuck and I struggle to open it - I thought this was because I lie on the tank on long trips and maybe I've stuffed it as a result. Again its something that occurs intermitently. Any idea's?

The cap has a vent Rob, which releases air pressure from the tank as it heats and expands due to increases in temps and sun. There is a drain for this vent inside under the key cap around the outside of the filler neck. (pop open the cap and look to the left side of the filler hole and you should see the little drain hole) If this drain is blocked the fuel will have nowhere to go and will start leaking out through wherever it can. This was the first thing I checked with mine, as it is common to get crud in it and block it up. To clear it, open up the cap, cover over the filler hole with something and blow some compressed air through the drain to ensure it's clear! If that doesn't fix it, let me know!

I havn't checked today, but I think my issue was just the springs were not placing enough pressure on the rubber to create a seal. I just pulled it apart and stretched the springs as a temporary fix. If that works, I'll order some new springs. I think maybe cause it has been sitting dry for so long the springs have rusted a touch and lost the elasticity!

ThanX a heap Marty... I will sus that out before the HG trip! Cheers.
ps. seriously, I'm not a post whore - yet lmao

ThanX a heap Marty... I will sus that out before the HG trip! Cheers.
ps. seriously, I'm not a post whore - yet lmao

Just as long as you always remember Rob, ...... " A Lady in public and a Post Whore on the forum"