Seat Fire...Listen up!!

Quck note here, but another issue has developed on these machines. As everyone knows the exhaust runs under the seat to the muffler and then out the twin pipes either side of the muffler.

Last weekend, I was riding with 2004 RX-1 Mountain machine (buddy) who bought same time as me. We got to the U.P. after dark and pulled the sleds from the cargo trailer where I store both sleds. We quickly got them warmed and headed off for a mile to the gas station where we topped the tank with the intent of taking off from the cabin I own directly in the morning by-passing the need to fuel. NO BIG deal, done that often before.

One mile from the gas station I looked up to see my friends sled showering sparks from the exhaust as he ran along at 20 mph in front of me down the two track to the cabin. I blasted up to his side and yelled at him to stop.

He jumped off, and the seat burst into flames. The plastic around the exhaust was bubbling down, and smoke was billowing out from the heat vent.

We quickly grabbed some snow and started packing the whole area with snow. It didn't work, even with the snow pack all over the back the sled fire kept going. Finally, I grabbed the rear of the seat with my leather gloves on and ripped it off the sled. The foam rubber was burning under the seat on the extreme tail pipe and as I ripped it off and flung it in the snow, wires and all, we put the flame out.

The aluminum shroud covering the muffler was red hot, and the muffler was still, cherry red....I exaggerate none. This was scarey....because had I not been right behind him, he would have been continuing on down the trail ignorate of this fire. Also it was dark, and I could see the hot sparks coming off, and we old duffers rarely go trail riding after dark.

Here is what my friend said when I asked him if the machine was "acting funny" or any notice.

He said that the engine popped a couple times and maybe half dozen times he could feel the engine miss, like a plug that was working intermittenly. That is it.

I have no idea what happened there, but if you are going down the trail and you detect a misfire, or popping sound, get off and check. No joke.

If I had not been there the only way he would have known about the fire was if he looked back or his pants caught on fire.

BTW, the heat shield was completely penitrated and had huge cracks in the aluminum. This fire was intensely hot. I summize that the muffler had to collect raw fuel to get that hot in no more than one mile of the gas station. And no, he did not let it idle at the station. Nothing we had not done a dozen times before.

Please pay attention to this because somebody could easily get very hurt by this.....including somebody very inexperienced,.....like your kids, wife, etc.

Sled is at the dealer in the U.P. and awaiting opinion from Yamaha. Meanwhile you should know about this issue now. I checked my seat area on my sled and it is fine, but believe me, if she misfires or pops I will be off it like a rocket.

Now does anyone know where you can get a good fire extinguisher to mount somewhere on the sled??

All I got to say is Yamaha better treat my friend square, or he will sue. His whole weekend was blasted away.

So it had raw fuewl buring in the silencer because it had a fouled plug???

jtssrx said:

So it had raw fuewl buring in the silencer because it had a fouled plug???

Click to expand...

Hey I am no expert. But think about how hot it got? Something had to happen to get that muffler so hot, and perhaps it was a fouled plug, maybe a stuck carb float, etc.

It was acctually a question. It's possible. On my turbo when It would hit the rev limiter and the ignition failed then it came back I'd have fire come out the exhaust.

(We also seen a guy pull a RX1 off a trailer and had a problem starting it. When it finally started it shot flames out the exhaust and ignited the seat which had been saturated with gas from traillering.)

From "Fuel shut off (full tank when trailering)"

We also saw one run for several minutes on the trail, after trailering, before the exhaust was hot enough to ignite the fuel.

Man thats scary keep us all up to date on this one will ya!

Yikes! I think Yamaha would like to see that. They just might even fix it for you, even if it isn't under warranty.

there also may have been a problem with the baffles coming apart in the muffler. and not letting the exhaust flow threw properly. this is a problem that Polaris had with some of there 98 600 and 700 twins. the muffler would turn cherry red and start on fire.
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they would indeed start running very poorly and sparks would fly out the exhaust. may be something else to look at.

Or there might have been some kind of animal nest inside the muffler that caught fire!
I've seen that on some machines

But if the nest was in there, you wouldn't think that it would get that hot. Maybe I'm wrong.

As JTS said, It sound's like it was not running corectly and he should have stoped, Instead he kept going and filling the exhaust with raw fuel and when the exhaust got hot enough it egnited and now the exhaust is a combustion chamber and the motor is pumping air to it. IT WILL GET VERY HOT!!!!!!! IMOP Yamaha can not be there to tell you when your motor is not running corectly and that you should stop running it.

This is why Yamaha needs to get rid of carbs, take the cold start enrichment step away from the user and let the FUEL INJECTION take care of the rest.

The only thing that would heat the exhaust to a "cherry red" temperature, is fuel in the exhaust system!

Which brings me to another point. Yamaha needs to provide FUEL SHUTOFF valves of the correct diameter (to minimize restriction) for trailering, as long as they insist upon selling 90s 4-stroke technology with 20s technology carbs!

I wouldn't doubt there was "spillover fuel" from trailering, being blown into the exhaust and burning nicely in the exhaust!

Ya know, you could have been severly injured (burned) if you buddy was in front of you and didn't catch that!

Man, as soon as that flame caught up to you Nylon bibs and jacket, you'de be a hurtin unit!

Nylon burns real quick and sticks to your skin!

Not cool!

Mike Sylvester of Flat Rock, MI had the same issue. Yamaha claims that his was the only in the country that did this.

One of the plugs kept fouling and didn't realize that the power wasn't there as he was new to the machine. Gas kept dumping into the exhaust and finally lit and the machine started on fire.

FYI, it might be a good idea to try and look up his number online and call him - I believe they went good on his machine and gave him a new one.

Brad

If he had red hot embers flying out and not flames it had to have been something in the exhaust. Like was stated above the exhast would push out unburned fuel to the tips and it woudl be a flame if the muffler is not restricted. To get embers there must have been something int her breaking up. A motorcycle exhaust has packing around a baffle that could cause this but I thought the RX1 had baffles like a car muffler please correct me anyone that has gutted theres and there was packing? I have seen timing mess up and cause issues of red hot exhaust pipes cam timing ignition timing but to rich either flows out the tailpipe or gets burned at the end of the tailpipe