My engine mounting screws keep vibrating loose. I've got the day off tommorrow and want to go to the field. I meant to get new Bolts and locknuts but had to work late and didn't get a chance. I really don't feel like waiting till 10:00 for the shop to open. Will locktite be ok for a nylon mount by great planes? I've heard somewhere-I can't remember, that locktite would eat plastic. Is this true? I think my mount is nylon but not sure. It's the adjustable one by great planes.

The Loktite won't hurt the mount. At least it didn't hurt mine. I only had limited success doing it that way.
So don't give up the idea of a nut&bolt. later daveo

You should also be using 'nylocks' [nylon insert locking nuts] too.

and/ or double nut the bolts. that is, tighten one nut against the mount, then add another nut, tightened against it..

One thing with using locktite; the bolts and holes need to be clean, free of oil. I've never used it on a plastic mountso can't comment on that.

Jim