Replaced piston and....

[CstMCgR]

My room mate had a friend ride his pred and in the process didnt check oil before he left. Well to make long story short he toasted the rings and scratched the cylinder all up. He replaced the cylinder with a new one and went to a high compression piston. They put the Pred back together and it wont crank now. It's in time has fuel and has spark, and plenty of fluids.....Any Ideas??? I am trying to help him get this thing fixed cause getting tired of going riding without em.lol....

[440exnacsracer]

did he go back with a stock cylinder? if timings right, spark is there and the fuel mixture is right, it should crank. does it turn over extremely slow? to crank mine for the first time with the new piston, i had to pull it off. good luck
Ben

[the predator]

if your cylinder has honed again before installing the piston you shouldn't have trouble getting the piston to move....did you coat the inside real good with oil before insatlling?

[440exnacsracer]

cant hone predators,...aluminum cylinder with nikosil liner, you score it, you bore it,....unless of corse you want to reline it for around $300

[jltld]

How do you know it's in time and has spark if it won't crank? Does the starter turn over or in a bind?

[the predator]

i went big bore. becuase of a mud drag incident...lolol...there was no salvaging the cylinder

[CstMCgR]

How do you know it's in time and has spark if it won't crank? Does the starter turn over or in a bind?

It is a brand new cylinder straight from Polaris.(my buddy gets cost discounts at one of the dealer..the new cylinder cost him 235)

Yes plenty of lube.

and how do we know about spark?? you take plug out of cylinder, plug the wire onto the plug and touch the frame while you bump...you will see it spark.

Why did you have to roll start it??? You are the second person that has said something about that. My room mate to has a friend that just told him lastnight that they had alot of problems starting his the first time.... but after that it ran like a champ. We shall have to try that this weekend.

[440exnacsracer]

ive had to roll start several of my quads with higher performing motors. even with the sleeve "wet" it still takes alot of force to get that new piston to slide. once the rings get broken in, it doesnt affect it. also, with the higher comp. piston, he probably has closer tolerances and tighter ring gaps, yet again increasing friction. hope it cranks after you pull it off.
Ben

[CstMCgR]

This Saturday is supposed to be a good weekend. We are going to pull it behind my 400...heh...imagine that. We are hoping that it will crank up after this. Thanks guys for information.

[the predator]

did you check your valve clearance? you might want to if you didn't....intake should be .006" and exhaust should be .010"