Guys,
The motor mount that came with my Aresti ARF is for .40 sized engines. The FX .61 I'm going to use is too big. No way to modify it to work.
I was wondering if there is a mount that I could buy that will fit right up to the pre-installed blind nuts in the fire wall, Or are these only going to fit .40 sized engine mounts?
What would you guys do? I am also concerned about accidentally changing the thrust of the engine. (height, not right or left thrust)
I have never had this problem, and got to thinking that IF I had to change blind nut locations, and change engine mounts, I might screw up the geometry of the plane. Thanks for any help.

Draw an X between the existing holes to find the thrust centerpoint. You may find an adjustable mount that will fit your engine and the current holes; I have a mount that fit my ST45 and ST75, so maybe you can find a good one as well. If you need to adjust the blind nut holes, you will know where the center is.

FlyFalcons,
Thanks a lot. Also for all the other posts of mine that you've responded to. Always helpful. I will look for an engine mount that will fit at the local hobby store.

Paul,
I fly my Aresti with a Rossi .45 and it is more than enough power for this plane. It's very fast and verticle out of sight. I have heard of guys snapping stabs with .46 fx's. And I would double up on those wing bolts if I were you.

I have a O.S. 70 FS in mine swinging a 12 x 8 APC at 9800 rpm. I had to open the sides of the mount to get the engine to fit. I run full speed downlines without any problems. Putting in a 4 stroke engine is the way to go!