Hello from chrisnbush in Richmond NH
I currently have a CH80 frame mount, that I bought on EBAY (!), and also a tire roller rear mount that I got from livefastmotors.
Have had the routine problems with the frame mount - mounting clamps breaking, mounting studs breaking, air leaking into input manifold, stripped head stud. Also, have learned how NOT to replace tire inner tubes. Love the frame mount though, it is cool and has more power than the tire roller rear mount. And I feel I have solved all of the problems at this point, with this CHEAP motor I got on Ebay (from what I have read, my next motor - this fall - is going to be from DAX, I think).
I got mounting clamps from DAX, I think this will not break - also made my own engine studs from threaded rod from the hardware store. Don't know what grade steel this is (there are good and bad grades for these mounts if you read around). I have double nuts + washers on all engine studs. The big thing I think helps, at least for vibration is that I expoxied sleeves made of old inner tube around the V of the bike, where the engine mounts go. Seems to help the engine from shaking apart - I just check mounting bolt tightness FREQUENTLY. Don't feel thread locker is much use as I am always tweaking the tightness out of (bad) habit. And, by the way, if oil ever works its way into the mounting holes, thread locker is useless anyway.
I have about 300-400 miles on the bike now, it is an old Schwinn - real sturdy rims and spokes. I have oil seeping out of the area in the head where I have ONE stripped head bolt stud. As I am concerned about blowing the head gasket I just (today) purchased some threaded rod and 2 straight steel braces with stud holes on each end - I intend to put 1 brace on top of the head (towards the front where the stripped stud is), and one way down on the bottom of the engine. Then a threaded rod on each side, rubber below each brace against the engine, and tighten with bolts and lock washers. Think of a big box that you can tighten up two sides on. Thinking this will put enough pressure to assist the stud. The test will be to see if I can get the oil to stop seeping out of the head gasket. The compression is still excellent, so I am pretty sure it isn't blown. I will post pictures sometime.
The air leak in the intake manifold (which is evident when the engine stutters and looses power at higher throttle levels) was solved by a tube of permatek gasket - be sure to get the oil resistant variety.
My rear tire roller model I actually built for my wife. It is more dependable, although has less power. Slightly better gas mileage, I get 88 mpg with it vs 81 mpg for my center mount. Had a problem with the centrifugal clutch outer disk spinning off the threaded tire roller, and clamping up tight agains the engine seizing up the tire roller (!) when going down hills. As long as the engine is applying torque thru the clutch to this disk, the disk is "threaded" ON to the roller. The problem going down hills, I guess is that despite the centrifugal clutch, the engine still seems to be applying drag on the disk - the bike is trying to go faster than the engine (the engine winds up going down hills), and the disk is spun the OTHER way to loosen it. Fixed it by applying epoxy to the threads and putting the clutch disk back on. No more modifications to the drive unit on this one !
Other than that sort of scary problem, the workmanship is excellent on this tire roller device + engine (no loose screws !)- again LiveFastMotors was the supplier. Yes, the tire roller model doesn't do well in the rain, but you can improve things somewhat by REALLY clamping the engine / roller unit down on the tire.
Well, thats it for now - I will be posting in the future. Pictures are coming, etc.