Gas cap

[insomniaticnotw]

Well my little Ninjette doesn't just let out a little hum, she screams at me. Constantly. When she's in direct sun, sitting in my garage, going 70 down the highway, you name it there's a squeal louder than the chain and wind noise. I've done the gas cap labotomy, or rather the guy who I bought her from did it, and it looks like they may have nicked a diaphragm in the process of doing so. As I've been looking about I haven't found just a diaphragm for sale, and have been looking into just replacing it with a keyless spin cap.

I was wondering which caps members here have tried, any issues with fitment (water getting into gas etc.) I'm not super worried about somebody stealing my gas, I mean if you're gonna take 3 gallons out of my bike you probably needed it more than I do. I've found some off Ebay for ~26 bucks and I've searched here and seen SlingShot Racing thrown around as well. Thoughts?

Thanks,
Kalin

Edit: It's a 2008

[Ghostt]

The biggest problem with aftermarket racing style caps is the venting needed for the fuel to flow properly. No venting, no flow like putting your finger on the top of a straw and removing it from the liquid.

I've done the diaphragm removal on both my EX500, and Ninjette and have had no issues with water, etc....

The biggest cause of water in the fuel is due to the drain gets clogged.

Hope this helps you out, here's my write-up on the diaphragm removal


Sounds like it could be a venting issue, no worries it's a free and easy fix,

You need you to disassemble the gas cap and remove the two small red diaphragms, assuming this is your only problem.

The diaphragm gets hard and losses it's flexibility and gets stuck, and doesn't allow proper venting.

IMHO this modification should be done regardless to prevent future problems whatsoever.

They are ment to vent the tank, but in the case of an accident not allow gas to leak out, but more often cause problems then they fix.

Here are some pictures to help you.

The plastic piece houses the two small red diaphragm pieces, this one being mine, they are already gone, and you can leave the plastic piece out all together, as I'm going to do now.

Some things to watch out for are, there are 5 small springs under the round collar, and a small round collar as well on the locking mechanism, don't lose any of them.

Good luck.

[insomniaticnotw]

Lots of information on that one Ghostt, thanks! Unfortunately I think that might be a Pre-Gen 250s cap, I have a New-Gen 2008 and it disassembled like this. I was under the impression that the 2008-12 had the vents and drains directly on the tank?

[ForceofWill]

I've had an SSR cap for a long time, no issues ever. It's great.

[RacinNinja]

Originally Posted by insomniaticnotw

Lots of information on that one Ghostt, thanks! Unfortunately I think that might be a Pre-Gen 250s cap, I have a New-Gen 2008 and it disassembled like this. I was under the impression that the 2008-12 had the vents and drains directly on the tank?

Just the overflows....the vent for the tank is still in the cap. The cap seals the tank with a rubber seal, therefor the cap must also vent to keep fuel flowing.