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Author Topic: M91 #2 Repaired & Modified to Run Slower with Lower Compression & Softer Springs  (Read 315 times)

Stoker

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A couple of questions Gil.

That does seem to be a whole lot off the top of the piston, but one thing I've considered doing with my M90 is to C'bore & cone the spark plug hole in the head so the spark isn't lost in such a deep hole, but rather has better "access" to the compression chamber, which would also lower the compression by increasing the volume. However, proximity to the valve seats would be the limiting factor, and would not really allow much of a bore increase nor chamfer, thus not much decrease in compression. What do you think about that approach?

The softer springs from the motor brushes seem to be helping too. Do you recall which specific motor or tool those brushes are supposedly made for, as my local Ace only seems to list them as replacements for specific brands of power tools.

That polish job really makes the radiator jump out .... making the whole engine more eye-catching!

Seems to jump around a bit less now too!?!?
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