Rear mount studs broke, any good fix???

[danlandberg]

I have used grade 8.8 bolts, and still had the breakage problem! The most important thing is mount angles!

[Al.Fisherman]

I have only used the stock mounting studs that came with the kit. Are the grade 8 a little on the brittle side, another guy from the other mb site said they can be, wondering about this upgrade.

Use a grade 8.8 as this is a metric measurement which is about equal to a US Grade 5. Anything over a metric 8.8 is overkill. A 8.8 can take MORE torque then the cast aluminum these engines are made of. A 6mm torque is 50 to 66 INCH pounds and a 8mm is up to 204 INCH pounds. I use 50 and 150 INCH pounds. For foot pounds divide by 12.

I will NOT mount a engine with the stock OEM studs. I also use red locktite and either double nut or use nylon locking nuts. 5 builds nar a problem with the mounting. Like I said before PROPER mount alignment IS A MUST.

http://www.motoredbikes.com/album.php?albumid=1018

[AussieSteve]

The most important thing is mount angles!

Exactly right, Dan, (in a nutshell). If everything is mounted squarely and firmly and there are no gaps to be taken up during tightening, there shouldn't be a problem.
Of course, that means whatever fabrication is necessary to make the front mount fit properly and even the back one if absolutely necessary.

I've personally never had a problem with stripped threads or broken studs anywhere on my engine. (I don't use a torque wrench either and never have except on car engine head studs.)
In fact, it's never missed a beat, except for a stuck slide.

[steveonbroadway]

Im not sure but ive seen alot of bikes sold with a rear tube of 1.250 thousand and then it spreads the studs and cracks the case too.. On brand new bikes never really rode? Im working on a good machined fix for this, just might cost me $750 for a nice milling machine, My bike has 1.125 tube so no problem for me, I hope...

[danlandberg]

They have a new mount system out now. I think I thought of it first, just never built one. Needed this type of system when I built a Micargi D.I.Y. kit. The M-50 frame was/is NOT made for these china made engines. I had to do a lot of mods to make it work. Then it was stole in Utah It's in the "stole bikes" forum. I have had another one stole 3 weeks ago here in LA CA. I'm tiered of building great bikes for thieves!!!