Mid-air shutoff?

Hi all, I was riding yesterday at the track-'02 426F. Put in a long day and and all day long bike was working great-as usual. At the end of the day I was going off of a table top, was in midair, and the motor shut down. I pulled in the clutch landed and pushed off the track. My bike, at least the fuel petcock, had got super hot-gas bubbling in the tank. I have a Clarke 3.2gal tank, so I think that might be part of the prob with that issue. The radiators didn't seem to be boiling over, however. I tried running it on the track, and in N, but I couldn't get the bike to self shut down again, unless I was in the air. I am assuming because the rear tire was spinning without any resistance.(???:applause: ) I tried messing with the fuel screw, went out a few times, and each time the same thing. Shut off in the air.

I had just checked valve clearances. All were good, but one exhaust. It was snug, but just in spec. (prob not now.) But not sure if that would have anything to do with it anyway.

Has anyone experienced something like this before? Any ideas on what the issue is? Might give me a head start at where to start.

Oh, and last night and this morning it fired up and ran as it usually does. I didn't get a chance to go to the track and see if it overheated.

Any thoughts would be most appreciated.Thanks!

Sounds like it vapor locked.

I've never had this happen to me so I don't know the solution, whether your gas is boiling do to the gas tank being so close to the exhaust or if its a faulty gas gap.

You might want to do a seach of "vapor lock" while you wait for others to chime in.

Good Luck

I bet your gas cap is bad and not venting correctly. I would start there first.

X2. Sounds like a venting problem and you got vapor lock.

If you still have problems, it wouldn't be a bar idea to check the float bowl.

I have also seen real dirty air filters do that too. If you been riding all day and near the end of the ride it gets real dirty...

Ok, so yes, I am a dummy. I did notice after the fact that the vent hose for the gas cap was on upside down, making it a no-vent hose...so that would make sense.

It did occur again after I put it on correctly, though. Thoughts??

Also, does anyone have a good fix for keeping the petcock and fuel line from getting so hot when running a big tank?

Check with your dealer, I had the same thing happen with 2 02 426's. Both of them did it but not often. There may some type of service buliten from Yamaha. Good Luck!

When I ran an oversized Zip-Ty tank, I used Header wrap on the fuel lines. I can't say for sure if it was truly necessary, but I didn't like the idea of how close to a heat source the fuel lines were. I never had any problems when I used the header wrap, but maybe it would have been o.k. without it. I remember reading somewhere that Ricky Carmichael's suzuki back in maybe 05' had some heat issues with fuel, that they had to fabricate something to alleviate it.

I found a foil tape at Home Depot in with the galvanized vent ducting that I use to tape the crossover line to the bottom of the tank on the right side of my IMS tank. It's a peel and stick kind of thing with extremely sticky adhesive. I stuck a layer of it on the inside of the tank, just because I could. I thought it could help reduce the heat absorbed by the fuel tank from the engine.

I found a foil tape at Home Depot in with the galvanized vent ducting that I use to tape the crossover line to the bottom of the tank on the right side of my IMS tank. It's a peel and stick kind of thing with extremely sticky adhesive. I stuck a layer of it on the inside of the tank, just because I could. I thought it could help reduce the heat absorbed by the fuel tank from the engine.

THat stuff should work, I'v used the same stuff to protect my # plate form the muffler and it worked.

THat stuff should work, I'v used the same stuff to protect my # plate form the muffler and it worked.

Yep. My 250F didn't come with any reflective tape on it. It gets hot very easily.

All it is is aluminum foil with adhesive sprayed to the back of it...

Do the repairs that others suggest, but also get on your knees and say a prayer. Having a 426 stall in mid air and not going into an endo is something to be thankfull for.

It it was a large jump, you are lucky to be able to type right now.

There was 2 riders, at a local track, that just endo'ed bad last weekend. Both were within a half hour of each other. One broke his back and one broke his neck. The one that broke his neck is still paralized right now, but they are hopeful for a full recovery. My .02 is the small double was built bad a unexperianced tractor driver and built a poor jump. I only attempted the jump 3-4 times. It tried to flip me over the bars every time. You had to really pay attention to what you were doing to not flip over....

Like he said....get down and say a prayer....

Chad

I had a bad endo and the bike crushed me and fractured my pelvis.

Good times.

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