Polaris RMK 2009 600cfi piston failure

[ntm_08]

What is the cause of this ? Only thing i have found is a broken bellows (membran) in the exhaust valve. Could this be the reason ? It`s mostly on the intake side but there is some on the exhaust also. And if i look at the head it shows that this is not the first time this cylinder have broken down.

Thanks

 

[skibreeze]

Early season burndowns are often fuel related.

 

[ntm_08]

Early season burndowns are often fuel related.

This is from last year, spotted befofore use this season.

 

[retiredpop]

The piston looks okay or at least the top does in the photo. Lack of oil or snow ingestion? I don't see any piston wash either.

 

[ntm_08]

Any input would be greatly appreciated. Is there any known issues with this type of engine that would cause this ?

Thanks

 

[diamonddave]

Is this motor a CFI-2 or is it a CFI-4 ?? The difference is 2 injector vs. 4 injector

Not sure how many miles since the possible previous failure but fuel pressure or lack of volume from partially obstructed an fuel filter and or dirty injectors have surfaced a few times. I would highly recommend having the injectors flow tested and ultrasonic cleaning done by Dr. Injector and replace fuel filter. Then after its all back together verify proper fuel pressure.

Also verify correct TPS adjustment and function along with proper oil pump adjustment. I have come across a few oil pump cables that have cracked at the adjustment threads which allowed way too low of oil consumption.

Poor quality fuel regardless of time of year is also always a possibility.

 

[SaskRMK]

pull your airbox/TB's and toss a telescopic mirror back there to ensure you have no air bubbles in your oiler lines. I lost compression last season due to a leaky oiler that was pulling air into the oil system. Like mtnhorse said I'm a true believer of fuel filters EVERY season. I simply blow tested mine after a swap and it was scary how restricted it was

Good luck!

 

[ntm_08]

Is this motor a CFI-2 or is it a CFI-4 ?? The difference is 2 injector vs. 4 injector

Not sure how many miles since the possible previous failure but fuel pressure or lack of volume from partially obstructed an fuel filter and or dirty injectors have surfaced a few times. I would highly recommend having the injectors flow tested and ultrasonic cleaning done by Dr. Injector and replace fuel filter. Then after its all back together verify proper fuel pressure.

Also verify correct TPS adjustment and function along with proper oil pump adjustment. I have come across a few oil pump cables that have cracked at the adjustment threads which allowed way too low of oil consumption.

Poor quality fuel regardless of time of year is also always a possibility.

It`s a 2 injector system. ?

I have ordered new fuel filter and oil filter. Wiseco piston kit, new bellows and springs.

How do you pressure test the fuel pressure and how flow test the fuel injectors. My local Polaris dealer have no equipment for testing this.

Thanks

 

[ntm_08]

pull your airbox/TB's and toss a telescopic mirror back there to ensure you have no air bubbles in your oiler lines. I lost compression last season due to a leaky oiler that was pulling air into the oil system. Like mtnhorse said I'm a true believer of fuel filters EVERY season. I simply blow tested mine after a swap and it was scary how restricted it was

Good luck!

I will check for air bubbles.

Thanks