



I only had 90 PSI of compression on my Polaris Trailblazer 250 2 stroke, and I figured you guys would know what to do.
I got this quad for free from my neighbor, and I always had this issue of it shutting off after 20 mins, so I did a compression test and found that I only have 90 lbs of compression. Granted, the engine was cold, but that’s also the only way to know, because it doesn’t really run at the moment.
I’d just like to get it running as cheaply as possible, I don’t need to make 130 lbs of compression or anything like a new motor, I’m not racing it, and I’m not using the quad for work, just as a cheap trail rider. I just would like to know where I should go from here.
It looks like it’s had some pretty bad piston slap, the piston skirts are pretty worn and the block also has some chatter marks but nothing that catches a fingernail. A local shop said that I should just hone it and throw a new piston in, but he didn’t look at the block with a bore gauge. I also noticed some shallow pitting near the bottom in the cylinder.
So should I just get a new 72mm piston, a new jug and piston, or rebore the stock jug and get an overbore piston? I feel like to get it running cheaply a hone and new piston isn’t a bad idea, but I’d like to hear some advice from you guys! Thanks in advance