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800 assault engine runs rough at idle- rpm drops

B
Mar 29, 2019
3
0
1
2009 800 Assault RMK- efi
The engine will start just fine, but the rpms fluctuates. Sometimes higher but mostly lower and then dies. Hard to use PERK when it wont idle right. I have good fresh gas. proper temperature new plugs. Could this be power valves? :face-icon-small-con

and would this cause problems when reaching high rpms when racing across lakes and meadows? Because, the engine light will start to flash (but I never counted the flashes.....) The flashing stops when I restart the motor and it runs fine.

Thanks for any insight into the issues
 

retiredpop

Well-known member
Lifetime Membership
Jul 3, 2001
1,350
295
83
Calgary
It doesn't sound like a power valve issue. It could be a fuel supply issue. Maybe the fuel pump is going or just a dirty fuel filter.
 
Last edited:
More than likely your down on compression, do a compression test and replace the pistons before they explode and take out your bottom end. Those motors scrape the pistons on the intake side and will literally knife edge the piston skirt till the piston shatters or breaks off the cylinder skirt. Well known for those motors. Best fix is the cylinder shim fix.
 
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