i had a frame like that, for the lower engine mount, i used longer studs, and a ball peen hammer to make a small dent in the side of the bike frame so the stud would clear it without grinding or rubbing. lasted the life of the bike until i switched frames. wish i didn't throw it away.
Update: Engine is mounted after a P.I.T.A. install. The downtube posed a big problem, so I "macguyver"ed the mount a bit and it worked out fine. The countershaft box was tough getting off, the main problem was the extra long screw, it wouldnt budge and I ended up stripping it. I solved that problem by using a pair of visegrips. Just about to start the engine, and despite the problems I'm looking forward to it.
i recently bought the same bike,but i returned it,and picked up a higher end bike at my local bike shop, but i had the same question about the mounting until i found your post, im interested to hear how she runs.
It didnt take me long after I realized I was going, and what a rush! The problem was stopping the bike....probably should have thought of that sooner but alwell lol Anyways, I pulled in the clutch and the engine rpm just took off! Is this normal? The problems continue, I hit the kill switch and the engine kept going! I killed the gas and eventually it died out, after doing that I set out to find the problem with the kill switch, everything looked right. The red wire is spliced in with the 2 blue wires, and the black wire is grounded to the bike frame. No idea where to start with the engine rpm.
when you manipulate the throttle grip do you hear stuff "going on" inside the carb? Sounds like something is not quite right in there. Also check for the ubiquitous vacuum leaks in the intake area.
As for the kill switch, try grounding to the black wire coming out of the magneto, that is "engine ground" and a more direct path. Maybe you have paint or something insulating the bike frame. Or a dud switch. You can always put a switch in between the two blue wires, that is the preferred method.