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Engine basics => Engine set up tips => Topic started by: Mike Scholtes on June 07, 2015, 12:42:49 PM

Title: OS FP 40 viable as stunt motor?
Post by: Mike Scholtes on June 07, 2015, 12:42:49 PM

Don't hear much about the venerable OS FP 40S. I have one that was worked on by Lew Woolard probably 20 years ago with little run time beyond a careful break-in per Lew's instructions. Is thus motor considered usable for stunt? I recall hearing about run-aways and other problems but maybe with modern thinking on low-pitch props and RPM range, it would be more suitable? Don't recall at this point what Lew did to the motor, port height maybe.

I have an LA 40S that runs fine for me with low pitch prop, though not as user friendly as the LA 46, but maybe the same thing applies to the FP 40? People seem to disdain the LA 40S but maybe have not given it a fair chance.

Title: Re: OS FP 40 viable as stunt motor?
Post by: Bill Little on June 07, 2015, 01:20:08 PM

Hi Mike,

I would say that since Lew reworked yours it will be suitable for stunt.  More of a classic 4-2 run style but higher rpm range than the Fox .35.  I ran a Top Flite 11-5 cut too a 10 1/2 X 5.  Very consistent high rpm 4-2 run.

All of the runaway problems and such were coming from people trying to run the FP in the same range as a Fox 35.

BIG Bear
RNMM/AMM