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Has anyone had a problem with the gas caps cracking on these bikes? I just ordered my 4th OEM cap since I bought my 220 in late 2004. All of them developed a radial crack in the top that would start imperceptively small and then slowly grow until fuel started weeping out from it when the fuel sloshes around in the tank.

I just can't force myself to pay $60-$80 for an aluminum one so I keep buying the POS plastic ones for $15-$20 a pop.

Does anybody make a plastic one that is reasonably priced but better than OEM?

Not the cap... it's the tank I believe. A little out of round and the stress of flexing causes it to crack. Mine is a 95 and no problems...

I've replaced one on the KDX, one on a 2001 KX with the exact same failures as you describe.
Someone mentioned that the gasket gets soft or compressed, allowing the cap to become stressed due to the overtravel at fully closed, but I don't see where that can wedge into a tighter fit.
The tanks have cracked on various Kawasakis, and I have experienced that as well, but that's a different thread.
Otherwise, I'd like to hear the real problem / solution for these caps, as well.

There have been some instances of MaKaw covering broken/cracked caps well past their standard 'Under Warranty as Long as You Can Hold Your Breath' policy.

It's likely the dealer that makes that happen...but it starts with the owner doing some yelling most likely.

A BTW....but I've seen a whole lot of riders crank their caps down like they're intent on containing a tank-o-weaponized reisen. That certainly isn't necessary.

You do have a gasket in there?

I've had both KDX's and KX caps crack. But once I learned not to crank down on them so hard...duh.... that problem went away.

I screw mine down just finger tight. I've never had a gas leak problem OR a gas cap crack problem.


Well...fuel coming out of the tank when it's upside down with the check hose ripped off don't count, right?


Often I've noted that it's considerably harder to UNscrew than it should'a been having used a finger to lightly snug it. Don't know the whys of that.

I have had good results with the replacements caps from UFO. They are thicker on the top and are molded with a curve to increase strength.

Its just a bad design. With my old cap, it would seep gas out onto the tank. So, i started cranking down the cap tighter. Then i noticed a crack in the cap a ride or so later. The next ride, i didn't crank it on as tight, and it leaked, and the crack became an almost separation. I ordered a new cap and gasket. Put them on, went for a ride, and it leaked! WTF! So, I thought "maybe i'm putting the cap on too tight?" That was it. A nice easy snug is all ya need. So, with all the affermentioned problems with the tank, cap, etc, I believe what alot of us have done, is overtighten the cap when the gasket gets worn down, thus overstressing the POS cap. Just my opinion..........

I have had two OEM caps crack. Sitting in the sun too long I believe was the cause.

Anyway, switched over to UFO about 2 years ago and no problems since.

UFO it is then, Thanks.

I probably tighten the cap more than is needed but I'm not cranking on it. Each cap took around a year or so to fail and didn't leak a drop until the crack formed. Gasket is still in place on the current cap and I never noticed it missing on the 1st two.

The cap on my '89 XR250 is still fine, I've had the bike since 1998.

FYI, my WR 94-97 (93-95 YZ) cap fist a KDX neck just fine(same thread pitch)...As I had the OEM KDX cap crack, and a couple for the YZ laying around. Only reason I bring that up is that the YZ cap seems much better (thicker/stronger).

I'm using a cap from a '99 CR 250. No leaks.

I'm just saying, I believe the tolerance between the stock cap and gasket are too close. When one wears a little, the other will fail........UFO huh?

i bought a billet aluminum one from pitposse motorsports on ebay for $24.95 + $5.95 s/h. i just did not like the short breather tube vent it came with so i re-used the stock one.my friends are jealous. it is black anodized with some endmill cut outs afterwards.check them out .j$