Bob Denman
New member

I learned a long time ago, that when you're tinkering around with the output of an engine: you have better ask some good questions along the way. nojoke
"Pick it apart"? Exactly what did I ask, that makes you think that? :dontknow:
I have some very good reasons for asking questions:
I once took a 65 horsepower 432cc piston-port snowmobile engine, and built it into a 107 horsepower 513cc powerhouse.
It was :
bored
Stroked
Piped
Ported
The 38 Mikunis were bored out to 39.5 mm.
To deal with the huge power increase: it required clutching and gearing changes that went way beyond what might be expected.
The Operations Changes:
Engine rpm was only increased from 7,800 rpm, to 8,100... :thumbup:
It had to drink at least 91 octane fuel: it didn't like 87 at all.
I had to let the engine warm up completely; before trying to take off on the sled...
Basically; the required changes were not psrticularly onerous, and I ran that sled for 15 years!
But I had to ask a lot of questions about that build, and I had to learn even more to tune it so that it would run the way that I had hoped.
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