70cc HT just blew at 3,200 miles

[Purple Haze]

I have never had a bushing bearing fail on any of my HT engines provided some castor oil was used in the mix. However, I did experience a roller bearing failure that seized the engine. It was my fault though, I was going downhill at full throttle and well above the normal rpm range.

There are German and Japanese replacements for the wrist bearings. I priced them out a while ago and they were very expensive and would require a minimum 250-500 dollar purchase at 20 bucks a pop. Perhaps, it would be worth getting a quality roller bearing repalcement to prevent them from fatiguing and failing in the future????

I built a HT bike a couple of months ago and rode the **** outta it, then it quit running... water in magneto... so I figured I'd tear it down and improve it. When I removed cylinder, voila! NO BUSHING/BEARING! How could this thing even run, much less for 200+ miles? Found some scuffing on piston skirt, and some of the chrome coating was scuffed away on cylinder liner, but other than that it seems to be still in good shape. Think I'm gonna sand the piston, then order a needle-bearing for the rod, and put it all back together as a sort of durability test. Should be interesting to see how long it lasts.