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Discussion Starter #1 (Edited)
I was wondering, should'nt the top of the pistons carbon up. I rebuilt the same 600 I am rebuilding this year, last year, (It is a long story). I road it quite a bit and it didn't get carbon on the top of the pistons at all (Well a little) but I was expecting the whole top of the piston to be carboned up. What causes it to do this. Does it have to do with to much oil getting in (oil pump adjustment). Would this decrease the preformance?
Sorry that I keep posting so many messages let alone about the same machine each time but i keep coming up with questions as I get closer to rebuilding my engine. Any way hope you for give me.
Thanks for all of you guys help and to the web site... Extremely appreciated.
 

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Carbon is a direct result of the combustion process(chemical reaction), especially when using fuel in the form of both oil and gasoline which by the way are both fossil fuels. Carbon is one of the elements that make up the formula.

I think it's normal to have a little bit of carbon on the pistons, but there should not be any significant build-up of the black sooty stuff. Too rich of a condition, whether oil or gas, will produce more of a build-up. Keep your jetting within reason and a properly calibrated oil pump and you should be okay. Correct plug color and piston wash will help you determine how well the sled is running. Sleds with VES variable exhaust systems must clean this carbon build up off of the valves once in awhile. There's no getting away from it. Correct if i'm wrong...
 

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if your pistons tops are clean,no carbon or very little carbon in center, your to rich,the excess fuel is washing the tops clean,if your pistons are complete carboned up no clean spots,size of a quarter, by the ports you are far to lean.....you want a .cardboard. colour plug.


ves valves get gummed up from the injection oil,cheap,non synthetic will gum up faster then synthetic oils,but even they gum up just not as fast
 

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If you run a good synthetic 2 stroke oil like Amsoil. You should not see any carbon build up on the tops of the piston as long as carbs are adjusted correctly. The most you might see is slight golden brown translucent color depending on quality and efficiency of the fuel burn in the cylinder. Synthetic oils do not contain a carbon base oil and it is this carbon base oil which when burned turns to ash and leaves the carbon deposits on your pistons and inside your exhaust system.

Regards,
Nathan

Alaska The Great Land!!
 
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