Dude, I got a problem. After reading the thread about the "cracking frame"-syndrome I just felt I had to check out the space between my frame and engine spacer. However to check that I obviously had to loosen the bolt (forward right one). However, when doing this I noticed that the nut was just spinning on the engine side. If I'm not wrong the engine should hold it still, right? After a while I managed to hold it enough tight whith a 17mm tool (sorry, english is not my native language and nameing of tools was one of the things my old shoolteacher totally forgot to teach ;) to get it loose. However... now, Houston, I got a problem, how can I get it tight again, and also if needed loosen it again? The engine does not seem to support the nut enough. Now the nut also has gone edged so I guess I should try to get a new one but I dont think fresch edges will help much.
Is there anyone (in Houston? ) who got a solution to this problem i would pretty much appreciate this...
Btw I had 5 mm space between frame and spacer so i will put in a n extra spacer before I tight things up again ( if I ever will be able to ).

The nut should be held by the shaped space for it on the head. It is a pretty tight fit. Can you actually see it turning, or is the nut stripped? It is pretty small with a metal lock on it. If you get a new nut, it might be too large to fit there but you could try. It would be better to shim the gap on both the right and left motor mounts.

Thnx for your advice... and yup, it is turning. As far as I can see it does not seem to be striped. Guess that I have to get a perfect match so replace it. I notice that it is hold better if I push it "forward" but to get it in that place I would have to put schims behind it to get it in that position when tightening and it doesnt look like there is room for shims. have been thinking about using a TIG to put some extra metal (weld) on two edges on the nut to hold it still. What do you think?

That might work... Can you get pics of it?

Now fixed, had a guy weld two "flees"(as we say in Sweden) on the nut to make it stay... worked like a charm.