Project Trailblazer 250

[badtothebone250]

I thought I would post a build thread for anyone interested in reading/seeing some of the process of bringing an old polaris trailblazer 250 back to life. I bought the quad for my girlfriend to learn to ride. The quad was listed for $500 and I would have to drive about an hr each way the day I found it. When I called the owner about the machine, he said he had a "mechanic" friend take it apart and that it would need a top end for sure and there was a little play in the bottom end. I told him I could only pay $300 for a trailblazer needing a full motor rebuild and being in pieces. He said if I came that day I could have it for $200! I told him I was on my way! We arrive and I start going over the quad. the cylinder was still on but the head was off. The motor wasn't locked up but it did look like it hadn't been running in awhile. We loaded it up and I headed home.

The next day I decided to tear into it to see what I could find. I quickly noticed they had never even pulled the cylinder to determine what was really wrong with the motor. I pulled the cylinder and sure enough... carnage!

[badtothebone250]

Chunks of the piston skirts had gone everywhere! It also gouged the cylinder wall pretty good right about the exhaust ports. I knew the cases would have to be split in order for there to be no chances of metal being left in the bottom end. So the motor had to come out.

[badtothebone250]

I got the cylinder measured and figured it was going to probably take at least a 1mm overbore to clean the gouges out. A new wiseco piston, full gasket set, and a Ritter Cycle Racing oil injection block off kit with a new throttle cable from were ordered immediately. While waiting on the parts to arrive we decided to sand blast and paint the exhaust with a fresh coat of black.



It was also the perfect time to clean the carb inside and out.

[badtothebone250]

Once the piston arrived, I had the local shop I used to work at bore the cylinder and clean it up in the media blasting cabinet.

[badtothebone250]

Getting the flywheel off the crank was a bit of a challenge even with the appropriate tools. I split the bottom end apart to clean the chunks of piston out and make sure all of the bearings were in good shape. Everything went back together and new crank seals were installed to make sure there would be no leaks when it was back together. I installed the new wiseco piston on the crank and made sure everything rotated smoothly.


I then slid the cylinder back over the new piston. Sure is pretty!

[badtothebone250]

Finally tossed the head on and torqued all of the nuts down. I installed the block off plate for the oil pump from RCR. The motor is together and ready to go back in the chassis. This is currently where I am at. Plans are to get the motor in the chassis before the weekend and start hooking everything back up! Stay tuned!

[ScramblerXLE]

Cool project! Looking forward to watching it!

[badtothebone250]

Motor is in the chassis, but need to hook everything up still.

[badtothebone250]

Well this project took a lot longer than anticipated and I forgot to update the thread! The Trail Blazer is alive and running great! The girlfriend is super happy with her first quad and I took her for a day of riding at the local off road park last weekend. It was a little muddy but the polaris did great all day.

[badtothebone250]

The next step is to get the electric start working again and find a few remaining plastic pieces on ebay. She does not like pull starting it and I would rather have it working as it should anyway. Also the exhaust has been welded on and does not line up perfectly like it should. I think a RCR stage 1 kit is in the near future! We plan to take it out to the badlands in Attica, Indiana tomorrow for Labor day. She is loving riding so far and it makes me a happy man!