Polaris sled not burning fuel

[nuthouse]

I have a 2002 550 fan classic with 11,000 miles.
Last season I notice all my lights would dim and come back bright.
This season I went throught all my grounds, things look ok.
I rode. yesterday, got. about 5miles in and I have no top end, just bogg dwn.
Made it home, found the threads on top of the spark plugs were gone and on plug fouled.
Put new plugs in, have top end now but will not idle and it nocks.
Went throught all my carbs, done compression check, each cly checks 70 to 80 pounds,
I know that low but check my other sled, same as this one and pressure is the same.
There is gas in the air box, it seems like there not a hot enough spark to burn the gas.
I switch out coils and CDi boxes, still the same.
What up?

 

[polarisrider1]

I have a 2002 550 fan classic with 11,000 miles.
Last season I notice all my lights would dim and come back bright.
This season I went throught all my grounds, things look ok.
I rode. yesterday, got. about 5miles in and I have no top end, just bogg dwn.
Made it home, found the threads on top of the spark plugs were gone and on plug fouled.
Put new plugs in, have top end now but will not idle and it nocks.
Went throught all my carbs, done compression check, each cly checks 70 to 80 pounds,
I know that low but check my other sled, same as this one and pressure is the same.
There is gas in the air box, it seems like there not a hot enough spark to burn the gas.
I switch out coils and CDi boxes, still the same.
What up?

sounds like multiple issues. the light dimming could be the voltage regulator. 11,000 miles on a fanner is not bad.

 

[whitedust]

sounds like multiple issues. the light dimming could be the voltage regulator. 11,000 miles on a fanner is not bad.

Agree more than 1 thing needs repair. If lights dimming that is usually stator probably not worth fixing on 11,000 mile fanner & will completely fail sooner or later with no spark at all if it is stator. Gas in carbs sounds like floats are stuck in carbs & carbs need to synced. Did you replace with correct plugs don't want to run a plug that is too cool. Might be able nurse a few more miles out of engine but end is near.

 

[snake]

ya the knocking is not good! one trick you can do=remove plugs,get a screw driver that will reach top of piston,now very lightly hold screw driver on top of piston and rotate engine by hand until it comes up to tdc and keep going till it starts to go down.now stop and firmly hold clutch so engine wont move,now give a firm push down on screw driver=if you feel more slop on one then the other then you more than likely have issues. you will always feel a little slop from the piston to cyl clearance.you will have some fuel spitting back into air box even on a good motor,esp if its not a reed inducted engine.I'd be pulling either the exhaust or carbs and looking in those cylinders,compression checks can be very decieving sometimes! idle is characteristics are usually what suffer 1st on a marginal engine. remember an engine is just an air pump=suck,squish,bang,blow

 

[motor_slut]

550's can last 50,000 miles if you want to rebuild them enough to get there. So the common things to check for are:

Broken skirts, will run like crap and knock really loud. Time for a rebuild!
Cracked fan/cracked flywheel, will also sound bad and cause running issues.
Stuck choke, the old VM's were bad for doing this.
Crank seals, test with ether.

 

[nuthouse]

Found PTO side had broken skirt.
In rebuild now, bore the jugs .020 over and new crank seals ect.
Will put new voltage regulator on and start from there.