I'm building a Tutor 40 (first ever model) and have an OS 46LA engine. The prefitted mount is allegedly suitable for this engine according to the instructions. Problem is that the holes in the engine do not match the holes in the mount arms. The Irvine instructions appear to suggest that the two metal brackets they supply just sit on top of the engine flange and hold it in place by friction/force (the bolts going through these brackets directly into the mounting arms.
Is this correct or should the bolts be going through the holes in the engine and then into the mount arms (in which case I need to have a different mount - the other one supplied by Irvine doesn't fit either, even though it does have recesses in the mount arms that would help keep the engine stable). The OS instructions clearly show the holes in the flange being used to secure the engine in place ????

kj, sit the LA on the engine mount and move it forwards or backwards to get the best position for CG balance. Then the 2 metal straps fit over the side flanges of the engine and are bolted to the mount. You are not supposed to get the holes on the engine flange to match the holes on the mount. Although this seems a 'Heath Robinson' affair to mount th engine it works, I have seen crashes where the plane has gone in nose first and the engine mount has absorbed some of the force of the impact saving the firewall from being ripped from the fuze.

Hi There,

I've just come to the same problem. I bought my engine to fir my Goldberg Cub, but needed something to train on, so I got the Tutor 40.

My engine is an SC 52FS 4-stroke, and the only way to get it in without fouling the firewall is to use the front pair of bolt holes.

Do you have any smart suggestions, as I'm a newbie....

Thanks

Dave

PS. I have posted this elsewhere - but the aileron mounting ply came with a couple of 1 3/4 long, 3/8 cross section balsa pieces. these are not shown or discused in the instruction manual. Any ideas?