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Discussion Starter #1
I just bought a 2009 dragon 800 with 66hrs and +/-800 miles on it. The engine is untouched and has the SLP intake, exhaust and can as well as a power commander. I did a compression test and got 110 from each cylinder. I have only driven this sled enough to warm it up to do the compression test. The previous owner bought it new from the dealership and has run 1 gallon of aviation or Race fuel in every tank since new. My question is: Is this necessary? The previous owner swears this is the only reason he hasn't had any problems. I have a friend with a 2010 800 Dragon with similar mileage and setup (SLP stuff) and we just did pistons and cylinders with the fix kit.

Any thoughts?

 

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No. Waste of time and money unless you're running higher compression than stock.
 

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I would guess depends ding on what your purposes with the snowmobile. But i do agree with Rubi. go with regular fuel...almost sure your sled will run just fine. and bear in mind your snowmobile is NOT an airplane.
 

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Discussion Starter #4
I would guess depends ding on what your purposes with the snowmobile. But i do agree with Rubi. go with regular fuel...almost sure your sled will run just fine. and bear in mind your snowmobile is NOT an airplane.
I will be running the sled for deep powder riding with a bit of mountain riding in the 3000-5000ft elevation. I have access to 94 octane premium fuel so that should be adequate.
 

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Premium fuel is all I would run, no need to run the higher octane stuff.
 

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Every time you pull up to the gas pump, send me the $5.00 extra you would have spent on 94 octane. I'll send you some magic beans you can carry in your pocket that will make your sled sled run better. Running higher octane than your engine needs does nothing but rob power and economy. High octane gas is less volatile, and has fewer btu's of energy than regular gas. It will run cooler though, since it's making no power.
 

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If detonation was the common cause of engine failures in them, adding a gallon of high octane fuel may raise the octane enough to stop it.

Other than that, waste of money.
 

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Discussion Starter #8
I took a peak at the top of the pistons through the spark plug hole and saw a little bit of carbon build up and what looks like small detonation pits. A mechanic friend of mine is going to come over with his scope and we will have a better look before I decide whether or not to pull it apart for repairs. I find it strange that there would be detonation if he was running higher octane with a power commander, but I would venture to guess that if the fuel map is incorrect for this exact setup than that could be the culprit.
 

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Too be honest some of those 800's just blew up, ive seen a single sled go through like 3 motors. I just cant imagine that not running race gas would effect that considerably. Especially mixing in an extra gallon per tank.
 

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Discussion Starter #14
I chose not to use aviation fuel because it doesn't make sense to do so. Luckily I have two Dragon 800's! I crumpled the tunnel on my 2010 early this season and just finished pulling out it's engine last night. Going to do the swap soon.
 
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