Engine mount....KF IV-1200 w/Rotax 912UL

[GWright6970]

Question on fit.... the motor mount to the airframe.

There are obviously five points of connection to the airframe. So here is the background to my question:

I put a bolt in the bottom motor mount hole, and pass it through into the airframe mounting hole as a starting point. Then the two side points get bolts, and they align pretty well darn well with the bottom. There is also a wee bit more flexibility in these arms on the motor mount, so it makes for an easier alignment with the airframe points.

The top two points of the motor mount do NOT align very well with the airframe points. The aircraft top right (starboard) motor mount point is slightly low and outside by about an 1/8th of an inch. It is also about 3/16 of an inch away from the frame.

The left side (port) is a full bolt diameter, about 1/4 of an inch low and inside from the airframe attachment point and about 3/8 of an inch away from the airframe plate.

I can spread the top two arms of the motor mount, without mechanical assistance, insert two bolts and make them align, except for the distance away, which I read we can use washers to fill.

QUESTION: Is it acceptable to have some strain introduced on the top motor mount arms by spreading them about 1/4 to 5/16th of an inch?

Thanks for your replies!!

[Dorsal]

I had a similar issue and was told to muscle it in, seems to work fine I do remember it taking considerable effort to get alignment with offsets a bit more than what you have stated.

[mr bill]

Mine was misaligned also, but I pushed, pulled, swore a lot, but finally got all the bolts in. Hopefully with age, it will take a set to the new configuration.

[HighWing]

I agree with the others. I think I would also avoid the washers as the mount was fabricated on a jig and with the attachments tight, the alignment of the engine should be where it should be. The 4130 is tough stuff.

[GWright6970]

Thanks guys!!! I hoped that this would be the case....

I am trying to get some more work done in the next couple months so that I will have something worthwhile for Lowell to drive down and see!!

This is a great forum..... thank you all so very much!