Thread: 100:1 Mix
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Old 08-15-2009, 11:15 PM
Creative Engineering Creative Engineering is offline
Join Date: Sep 2008
Location: Clearwater, FL
Posts: 1,668
Default Re: 100:1 Mix


I had one engine that had bad crank bearings. The bearings locked up and the crank was spinning in the inner race. The engine continued to run; but of course it had lost a lot of power.

It wasn't noticeable from a typical diagnostic standpoint. The bearings are a loose fit on the crank. The engine would not attain it's normal RPM. The drag from the crank running in the inner race resulted as a huge loss in power.

Ball bearings really don't require that much lubrication...but excessive heat will permanently damage them...especially low quality bearings.

The oil is as much of a benefit for extracting heat as it is for lubrication.

In a properly designed 2-stroke, the fule/oil mixture "flow" is critical to keeping the bearings cool and lubricated. It's not just the engine porting for performance, but also the dispersion of the mixture to the crank bearings, the rod big-end, and the wrist pin.

Just a guess...based on what you described.

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