Im building a G.P. extra 300s. Ive chosen to go with an o.s. 91fx and will be mounting it on its side to accomidate a bison pitts. I have the engine mounted using the mount that the kit supplied. However, i can tell just by looking at it straight on that there is too much right thrust. I beleive the kit calls for 2 degrees. How do I measure this and does anyone have any thoughts on changing the angle without rebuilding the firewall. Will a shim behind the mount on one side work?, or a couple of washers?

G'day Mate,
What makes you think there will be too much right thrust, fly it & see, & adjust as required.
when you fly it, trim for straight & level flight at full power, fly away from yourself & pull up verticle release elevator & watch what the plane does, if it goes straight up, then right thrust is correct, if it yaws to the left, more right thrust required & visa versa. try it into the wind & do it a few times to be sure.

Thanks for the tips, but, the prop shaft isnt even close to the center of the cowl opening. Its looks too odd. The shaft coming out on an angle like that. Ill try and get a pic on here. Sorry if this seems like an easy fix to some, but I am still learnin.

not sure how to get pics on

Check out this "How-to":
[link]http://www.rcuniverse.com/forum/m_2629917/tm.htm[/link]

Ken

ok heres a couple

Got her figured out. I used a couple of pieces of steel banding as shims, drilled holes in them and put them between the fire wall and engine mount. Worked well. Still not sure how to do a proper measurment but it looks better now, will have to fly it now. Ran the engine, stared right up out of the box on first turn.