I have a 94' Polaris 600 XLT SKS and it has about 7,000 miles. It still has great compression and starts on second pull. The engine has never been apart and I just replaced the original hyfax. This sled has held up great and the only failure to date was a jackshaft bearing. I think that the tripple engines were the best. I hear about to many problems with the liberty engines. I will stick with old reliable!