ok. so i have built this 4 star 40 perfectly to plan. everything is together and covered. added my reciever and seros. slap on the 46 LA that the plans call for and the thing is EXTREMELY tail heavy!! so i move everything as far forward as I can and it is still tail heavy. i often add weight to the tail to balance most planes due to a larger engine. however, i did not want to add too big an engine onto this plane. i have been flying for a while and i hate adding dead weight to my planes, but i am wondering if i should remove the 46LA and place a heavier OS 91 4 stroker on it to help balance that weight. I know that the 91 is way more than needed (power wise), but if I am going to add weight to the nose it might as well be in the form of a larger engine.

has anyone had this same problem??? has anyone placed a 91 4-stroke on a 4*40??

its all in throttle control.......to a point...

any thoughts???????

I think the 91 FS would be a little overkill. You will end up flying the engine instead of the plane (this I know from experience). A 52 FS, or maybe even a 70FS.

Have you added weight to the front, to see how much weight you will need?

Seems like jumping from the .46LA (which is a feather weight 46) to a .91 FS is definitely overkill. Like Hooter said, see how much weight you need first, then find an engine that fits the bill. You might even find that a bearing .46 would take care of it.

My 4*40 ballanced right with a Magnum .44 gp (bushing bearing) and the battery right on the CG. I changed to a Magnum .40 XL (ball bearing.. heavier) and had to put the battery behind the TE of the wing.

The O.S. LA.46 is lighter than the Magnum .44. Not sure how close the .40 LA is in weight to the .46. Might just try a brass "safety" prop nut (and watch it need the battery to be behind the TE of the wing...)

*****

Note... all the above engines fit the same bolt holes.