Hi all,

My superhawk is my only vehicle and I put 300 miles minimum on her a week, rain or shine. For the second time now the bay area has been hit with a storm and in addition to roads not designed to deal with rain, and drivers who don't know how to drive in it, I've been having the following problem.

In heavy rain gas will stop flowing to the engine, it looses power and dies. The temporary fix has been to ride with my gas cap cracked. My mechanic replaced the line that allows air into the tank to prevent a vacuum from forming but the problem persists.

This has made for some very sketchy situations (once I almost flew over a barrier into oncoming highway traffic), and raises some questions:

1) Has anyone else had this problem?
2) Does anyone know of any permanent solutions?
3) Is driving with the gas cap cracked a bad idea? (I imagine a little water is getting in with the gas....).

Thank you for your help!

 

I recently had a Kawasaki ZRX1200 with a similar problem. The tank venting inside the tank had gotten plugged and was almost impossible to service. I bought a VORTEC gas cap. One of those billet aluminum ones. The have anodized caps and rings and screw on with a large sealing O-ring. The thing is that they are vented caps....They have their own venting system and do away with the stock system.
One thing though. Has anyone had the tank off recently? maybe there is a slightly kinked line that a tiny bit of rain water can close off.

 

ZERO- That may be, this bike has seen some action. I had a high side, had to lay it down when someone cut me off with a left, and it's been knocked while parked. The gas tank will actually shift a little if you press it in the right spots. I like the aftermarket gas cap idea, that might be cheaper than having my mechanic check the vent connections/routing

I'm particularly interested in whether cracking the gas cap in the rain could cause problems....

 

Easy fix. Mine had this. Water gets thrown up at the vent line as it sits behind the front wheel. It sucks it up.

I lifted the tank, identified the line and removed it. Ran it like this for months perfectly. I recentl put a line on that comes out the back of the motor on the RH side. Still runs perfectly in the rain.

Opening the gas cap is the clue. Mine would breath in if I opened it.

 

I agree with Mr. Spokes. Be aware too that these bikes are also susceptible to vapor lock if you fill the tank too high up the neck.

I had the bike stall on the Brooklyn bridge. Had to turn it off while rolling in traffic, take out the key and open the cap, shut it, put it in the ignition and restart the bike before I got to Manhattan. (happened to be in the rain too).

Find that vent line and move it and if that doesn't solve it try cleaning out the vent hole in the gas cap part of the tank with a piece of wire.

 

Careful routing of the vent line where the rain will not reach or its removal is an option, as is a Votec or Yoyodyne (a primo item) are solutions. I rerouted mine, cut it's end at a bevel and added a T-fitting under the tank. From the horizontal barb of the T-fitting I extended a short length of clear hose with some malleable stainless wire in it to keep it at 90 degrees so the hose was up and inserted a CG gas tank vent check valve to it's end. No more "vapor lock" (which it really technically is not).