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Ok, I FINALLY got my snowmobile out today. As pathetic as it seems, middle of Febuary and all. But what the hell, I'm sigle again, now I get to play with my toys! So I worked all day yesterday finishing up the little projects I've been putting off, and put on the new-to-me skis and replaced the spark plugs on my '96 Forumula III 600. After checking the fluids and all that, I loaded it up on the trailer and ran over to the station and filled the tank up with some 93, ran her around the neighborhood for a bit, and figured it'd be good to go today. So, after work today I stop by the house, get the sled/trailer out of the garage. I decided just to start it up and let it warm up while on the trailer, because I was only pulling it 5 miles to where I was going to drop it off. Anyways, I get out in the country and unload the sled. With the engine already warm, I hop on and go down the ditch. I noticed it felt like it was missing and lacking power. I decided that it must just be the remains of the old gas from last year that needed to get moved through the lines, and went on my way. One of my good friends from high school is building a house in the area where I was riding so I decided to swing by and check on the progress. I also noticed that along with the miss, when I would lay into the throttle all the way, it'd bog down and almost die. I figured it might have been the plugs fouling out. So I thought I'd just stop by the house and than head straight back to the truck, pissed off 'cuz I KNOW that the gap was set correctly and the plugs were brand new. NGK BR9ES plugs aren't as inexpensive as I'd like.

Ok, to wrap this up... I was sitting on the sled, admiring the progress on the house, when I started to smell an odor. I looked down at the hood of my sled and saw flames pouring out! So I killed the engine, threw open the hood and doused the fire with snow, and than MORE snow to be sure I got it out. It looked like the fire must have originated on the exhaust system, and nothing major was destroyed. The engine now breathes better with the giant hole in the melted bellypan. Outside of that, and some minor paint peeling and insulation torching, nothing else appears to be burned. Not even my new-to-me flex skis! My concern is, upon examining the trailer we noticed a large amount of gasoline had spilled or leaked on the the snow covered trailer deck. Where might this be coming from? The fire appeared to have started on the main silencer on the exhaust system (stock triple), and I'm afraid I don't know where to look for leaks/loose fittings in the fuel lines. Where do I look? Are there any common leak spots on this engine?

Also, what's the cure for fowling plugs? I think over the past few years I've spent more trying to correct that problem than I paid for the sled originally! Tried rejetting, had it to three shops, all "fixed it", all said the compression is "great". So I'm lost, I've ridden other FIII's in the past, and they rocked, why won't mine exceed 30mph??? I guess I'm rambling, but I'm just very irrated by all this, and I'm taking time out from looking for new bellypans! Thanks a bunch for any and all help!

It figures though right? We FINALLY get a few killer snow storms, and now it sounds like we may get some meltage here in North Dakota next week!
 

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All the carb cleanings and such wont cure some overlooked minor problems that lead to major ones. Upon cleaning the carbs did they check the floats to make sure they are right and if the float valve seats properly to shut down the fuel. If not that will fill or foul out any plug. Second, you should shut the fuel down for trailering to ensure that if a float is not seating right that it dont fill the crankcase with fuel and ignite in the case or flow out onto the bellypan and ignite that way. Even if its a high mile sled it will have considerable power display no matter what unless the motor is going. Once you notice a lack of power, stop right away so the fouled cylinder dont fill up with fuel, eventually it will catch fire. Have the carbs synced in the temperature and jetted for these temps or altitude you primarily ride in. Some shops just ASSUME your sled ran tiptop before you brought it in and dont always adjust the carbs or chokes properly. I had one cylinder run cold on me for about 5 minutes of riding just because my choke was not opening enough to warm the cylinder and i would dog or foul that cylinder all the time. The fire,though unfortunate, is a whole lot better than blowin out the case or crankseals running it when it dogs like that. I always have the fuel shut off and run it for a few seconds to ensure the carb aint full, DONT run it till it dies since it aint too good running a 2stroke out of fuel. Any carb, besides EFI setups, have a potential to flow into the cylinders from bouncin around on the trailer. Hope your still ridable, cosmetics dont matter on the trails, unless its pink parts on it...LOL
 
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