2009 arctic cat m8 engine problems

muddymama

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i have a 2009 arctic cat m8 with only 700 km i was taking off the y pipe and can and looked in at the pistons and noticed extreme scoring of the piston and cylinders it has never got hot anyone out there know why this could happen. iwas told this machine is one of the most reliable. as well is there a big bore kit for this machine thanks for your help on this issue
 

Himark

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i have a 2009 arctic cat m8 with only 700 km i was taking off the y pipe and can and looked in at the pistons and noticed extreme scoring of the piston and cylinders it has never got hot anyone out there know why this could happen. iwas told this machine is one of the most reliable. as well is there a big bore kit for this machine thanks for your help on this issue



whats "extreme" post some pics...just shine a flash light on the pistons. many of the 09s were TIGHT. some squeaked within 100 miles. some just lightly scored like mine. when i first looked myself i was WTF?! can you feel the scoring with your finger nail? couldnt on mine.

after 4200 mtn miles of not being nice to mine....ran strong as ever. i did the top end on it just incase.

check your compression too.

they all blow up...the cat 800 is known for being one of the really good ones.

good luck!
 

Modman

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i have a 2009 arctic cat m8 with only 700 km i was taking off the y pipe and can and looked in at the pistons and noticed extreme scoring of the piston and cylinders it has never got hot anyone out there know why this could happen. iwas told this machine is one of the most reliable. as well is there a big bore kit for this machine thanks for your help on this issue

What side of the pistons is the scoring on? Intake side could be snow ingestion, exhaust could be bad fuel (or lean).

There are tons of big bore kits available.
 

Pistonbroke

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I've got a 2009 M8 engine with a D&D 901 big bore kit in it for sale - would be perfect for you. PM me! Only 500 ish miles on brand new top end.
 

m8welder

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Burning previous years fuel in them can cause that. I blew my rings apart years ago from the same thing. Best to drain and put fresh fuel in every year.
 

muddymama

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you can feel scoring on the back of clyinder walls and on the front of the piston
 

kootenaycat

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Cold siezure? I've seen way too many people start it up, let it run for a minute while the helmet goes one then it's wide open down the trail! Letting it idle even for 5 minutes doesn't warm it up properly, I take it really easy for the first few km down the trail - 1/4 throttle and watch the temp gauge if you have one.
 

xxxmodrods

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Check the oil line on the bottom of the throttle body boot could be broke. Probably not but worth checking.
 
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glengine

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Before i sold my '09 M8's the had over 8000km's on them no issues origanl pistons and still ran strong. I'd suspect poor fuel or oil line off or the link rod from oil pump to throttle bodies come off. Rk tek makes a really good 925 big bore for that sled. One of my 2012 M8's already has over 7000km and runnin strong still original pistons.
 
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