Counterbalancer/waterpump assembly. Looses tolerance overtime and once it reaches +/- .015 of slop, you will throw out the mechanical seal. Goes unnoticed till it's too late.
In my case, the counterbalancer/waterpump unit was so worn, that it ground right into the lower section of the case ever so slightly. Which caused the cast aluminum case to have a slight fracture, and run lean which caused the motor to melt down.
@@KingSalmon Thanks for the heads up just I got done rebuilding a 95 scrambler 400 I did a new top end its bored one over I didn't do a bottom end cause there was no play in the crank and I read the bottom ends are strong on these. Looked like new inside the motor it holds coolant no overheating. Outside was a different storey the whole motor was just soaked in oil but I cleaned and polished the motor up repainted the whole frame I was doing it to sell but im going to hold on to it for awhile i like the power it has. I did notice at low idle the motor moves alot more then I thought it should. A little above idle it smoothes out I put new counter oil in I read the motor movement is just a natural polaris thing being a big 2stroke? I also had to pull the motor and fix all the motor mounts and bolts. I don't like setting the idle so high where the motor stops vibrating cause then putting it into gear it grinds I guess I gotta find the sweet spot for idle I probably have it turned down to much and the motors lugging causing the motor movement.
