I just acquired a 2003 Polaris trailblazer 400. It would start after a lot of effort. Then it would die after about 10 minutes. I checked compression and was getting almost 70 lbs. I pulled the head and both rings were broken. One was in 3 pieces, the other was in 2. I have ordered a new piston after having machine shop look at cylinder. I was told it needed to be bored 25 over. The oversized piston and rings are now at the machine shop with the cylinder.
My question is what else should I do? I keep hearing about crank seals. Should they be replaced? Anything else I should replace? What’s the best way to check the automatic oiler? The bike itself is in mint condition. I plan on using it for years to come. I want to get out and enjoy the trails. Any help is greatly appreciated.