Just finished breaking down and reasembleing the top end, ring gaps checked out fine, and the piston to cylinder wall tolerance was a little under .002, I did notice the rings were sticking in the grooves when compressed all the way, so I sanded both rings and ring groove with some 600 grit, reasembled and now am getting around 120 on dry tests, and 130 on wet tests. I am hopefull after well broken in the rings will seat a little better to the cylinder walls, Slightly boosting the compression 5 or 10 psi, I havent set the ignition timeing or tried to run the motor yet, I will work on this after dinner hopefully it will fire right up.

 

Ring end gap when placed in the cylinder should be between .008 to .016. As long as you have the compression up hopefully it will be okay. Premix the first tank of fuel 50-1.

 

Already had the fuel premixed, pulled it over a few times every other time it would backfired and pull the cored right from my hand a bit encourageing, I will adjust the ignition timeing in the morning and hoppefully it will run! Fingers crossed.

 

Well, tried it out advanced and retarded the timeing tried it in several positions, the most I got it to do was fire 2 or 3 times and that was after pulling like hell. I've got good fuel flow, I just dont understand, maybe I will check my coils again tomorow,got anymore suggestions.

 

When you said you pulled the piston out and checked the rings again,did you replace the head gasket or reuse the old one? If you did that could be a source of the problem. Plus pull the black wire from the reverse limiter module. It's noted for going out,retarding spark,just a bad idea that Polaris had as a safety feature. Item #33.http://www.cyclepartswarehouse.com/f...1989&fveh=5336

 

The head gasket was in good shape, I replaced it when I did the top end. I unhooked the reverse limiter, but that didnt go anything. The spark is still fireing 3 or 4 inches before the timeing mark on the fly wheel, lines up with the sight hole.

 

The cdi does take the place of the old condenser and points and does program spark timing and advancement electronically. It's possible even with a good spark,a cdi can be bad,it's just I've never really encountered one like this. On the old Hondas if you lost spark you could drop the cdi on the floor,hook it back up and sometimes they would run for a while. Any electrical module that has resistors and diodes can do strange things. Might be time to try a new one if you've exhausted every other check and the stator keeps checking out ok..

 

Just istalled the new cdi and same problems I did notice a crack in the plastic cover of the voltage rectifire, I dont know if this would cause any sort of timeing problem but at this point I am looking in every corner, I retested the exciter coil and it still reads as 120 ohms of resistence which is ideal.

 

Shouldn't but since it's tied into the stator the voltage regulator could short which could affecting other components.Just a guess,but since the case is cracked,I'd replace it. You've already gone this far.Polaris ATV Rectifier Regulator
See if these folks can help you. Your original Polaris part # is 4060087.