My frame looks like it's a little too small for my engine, but I really don't want to find a new bike. What should I do? Pic below.
I'm just using that part as a spacer, it doesn't fit either tube.The angle is wrong and there appears to be an extra part on the front mount. I think you want that part on the rear mount where it attaches to the seat tube.
Tom
I concur. The Seat Post should determine your angle. Take your time, think about this-with all of the above in mind.I'm not quite understanding here. What is the part you have attached to the front engine mount?
The engine needs to rotate clockwise as you look at your photo and sit lower in the frame. You might need a custom/aftermarket front mount but the rear mount should attach easily to the seat tube. That will give you approximately the right mounting angle.
If the frame tubing is too big for the engine mount saddles you can open them up a little with a grinder/file/sanding drum, but if the frame tubeing is too big you will have to fabricate both front and rear mounts...or look for another bike to motorize.
Can you provide a better photo of the rear mount where it touches the seat tube? That would help us offer more suggestions.
If you have spark plug interference with the frame the cylinder head can be rotated 180 degrees putting the plug facing forward. Also I think I'm seeing a water bottle holder screw head. That can be removed to give the front mount a place to rest.
Tom
Since the tubing is like 2.75, I just fabbed a mounting plate out of some steel sheets, and bolted it to the mounting saddle, sort of covering the U shape of the saddle. then I drilled holes for a U-bolt.Five to ten degrees shouldn't really give you any problems. Keep the angle as small as you can to get throttle cable clearance and you should be good.
What did you do on the front mount?
Tom
If you have 6mm studs then the max torque will be in the 50 to 60 inch pound range. That isn't much and can easily result in breakage if you heavy hand them.It snapped at the stud, right below the nut. I think it's 6mm, I because I have the 49cc engine.
Only one of them snapped, and I removed it easily. I found studs sold by the same seller that I bought the bike from, so I'll order those asapIf you have 6mm studs then the max torque will be in the 50 to 60 inch pound range. That isn't much and can easily result in breakage if you heavy hand them.
You'll need to remove the cylinder head and if there is enough stud to get vice grips on you should be able to turn it out. If not then you'll need to remove the complete cylinder to extract the broken stud.
Good luck. Let us know how you make out.
Tom