A couple of questions

Johnny_

Well-Known Member
Local time
11:07 AM
Joined
Jun 22, 2024
Messages
1,304
Location
Willow River, MN, USA
Ok, I'm back with 2 quick questions. I'm hoping to get a couple things done on my bike before spring, so come spring it'll be even more awesome lol.

#1. I'm having difficulty finding a CNC motor mount that will work. My bike frame is exactly 1.25" in diameter, and all the motor mounts seem to be for 1.65" frames. Anybody ran into this? Any suggestions? Are the motor mounts exactly 1.65" when clamped all the way down? If my math is right, a 1.65" motor mount on a 1.25" frame would leave 0.2" gap all the way around. I'd rather not have to use spacers.

#2. Is it worth it to upgrade the china doll CDI for a better one, like the one used on the Phantom? This is something I've been trying to decide on for a while, but I can't find out if it's worth it. Should there typically be a noticeable difference, or does it have a small enough effect that it's not noticeable except in certain extremely high-performance situations?

Thanks!
Johnny
 
You can make yourself one of those mounts. If you get a 1.25" shaft collar you can grind the opening on one side and make a plate like I did that bolts to the engine and goes between the halves of the locking collar. I used some angle iron welded together to make the T section of my mount. Easy peasy.

And the phantom replacement CDI from Bicycle Engines is made with genuine Yamaha parts. It's alot better quality. I'm not sure it does anything to the timing or not.
 
You can make yourself one of those mounts. If you get a 1.25" shaft collar you can grind the opening on one side and make a plate like I did that bolts to the engine and goes between the halves of the locking collar. I used some angle iron welded together to make the T section of my mount. Easy peasy
Like this?
It's 1/2" wide, do you suppose that's wide enough?
 
Another question. I'd like to get a reed valve, and window my piston. Is the amount of metal I'd be taking out to create the window gonna mess up my balancing, or is it a negligible amount of weight, since it's aluminum?
 
Links to eBay may include affiliate code. If you click on an eBay link and make a purchase, this forum may earn a small commission.
Back
Top