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I just bought a low mileage 2000 440 XC SP that appears to be all original and never raced. I don't have an owner's manual but was able to download a supplement which says this motor requires 92 octane fuel with NO ethanol. The guy I bought from said he used 91 octane fuel either with or w/o ethanol depending on what was available. If the higher octane was not available he used whatever he could get. He went on to say it has always run fine on what he used.

My question is rather I am going to have problems down the road if I don't consistently use 92 octane non-oxegenated, or what can I change to make it run on lower octane oxegenated fuel?

By the way, I plan on using the sled for fairly agressive trail riding.

Thanks in advance for any available advice. [?]
 

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Use supreme fuel only! Make sure your timing switch is on F or G.
 

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Originally posted by 440xcspRider
[br]I just bought a low mileage 2000 440 XC SP that appears to be all original and never raced. I don't have an owner's manual but was able to download a supplement which says this motor requires 92 octane fuel with NO ethanol. The guy I bought from said he used 91 octane fuel either with or w/o ethanol depending on what was available. If the higher octane was not available he used whatever he could get. He went on to say it has always run fine on what he used.

My question is rather I am going to have problems down the road if I don't consistently use 92 octane non-oxegenated, or what can I change to make it run on lower octane oxegenated fuel?

By the way, I plan on using the sled for fairly agressive trail riding.

Thanks in advance for any available advice. [?]

If you dont want to run 91 octane, you can recut your heads so that you can run regualar 87. Before you remove your heads, you need to check your squish with a piece of non acid core solder, remove your spark plugs, hook your solder at 90 degrees, long enough so it will go into the head, and touch the outside of the cylinder wall. Then turn over the engine, and compress the solder with the piston at T.D.C., and take the piece of solder to the guy machining your heads. Ususally, the squish will be around 0.060 plus or less 0.005
for a sled running 91 octane fuel.
 

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Originally posted by 440xcspRider
[br]I just bought a low mileage 2000 440 XC SP that appears to be all original and never raced. I don't have an owner's manual but was able to download a supplement which says this motor requires 92 octane fuel with NO ethanol. The guy I bought from said he used 91 octane fuel either with or w/o ethanol depending on what was available. If the higher octane was not available he used whatever he could get. He went on to say it has always run fine on what he used.

My question is rather I am going to have problems down the road if I don't consistently use 92 octane non-oxegenated, or what can I change to make it run on lower octane oxegenated fuel?

By the way, I plan on using the sled for fairly agressive trail riding.

Thanks in advance for any available advice. [?

Whatever you do, DO NOT RUN ETHANOL OR ANY OXYGENATED FUEL. ETHANOL INCREASES THE BURN TEMPERATURE, AND ALSO WASHES THE OILS OFF THE CYLINDER WALLS. IT DOES NOT BLEND WITH 2 STROKE OIL. OXYGENATED FUEL
WILL CAUSE YOUR ENGINE COMPOENENTS TO RUST, DO NOT RUN OXYGENATED FUEL OR ETHANOL BLENDED FUELS.
 

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Discussion Starter #5
Thanks for the info. I will make sure to use non-oxy or non-ethanol fuel.

Long term problem is that 92 octane fuel without ethanol is getting harder to find here in Minnesota. 10% ethanol is mandated for on road use in the whole state. On some trips like to the northern border near Canada, I may have to bring along my own fuel.

Would I have to do more than change the cylinder head in order to use say 89 octane oxy or ethanol fuel?
 

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You guys are crazy.

Just run it on the highest grade you can find at the pump and be done with it. In a pinch I'm sure it would run fine on 89 as long as it is jetted rich.

As for the 10% ethanol thing, most of us have been running it already for a long time. It really does not make a big difference. Maybe go up a jet size if you want to be for-sure safe.

Now if you plan on jetting it down till it's on the ragged edge so it is snappy and quick, then for sure every last bit of safety in your fuel is important. Usually the timing and jetting from the factory are safe enough that you have a pretty wide margin of safety if you run their recomended octane. If you run less, then you just reduce your margin of safety.
 
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