Yd100 performance issues

[ETHAN5438]

Even recommended makers make a bad plug from time to time. That one you have is in the wrong heat range, try a B6HS, with the gap set at .025-.028

Okay will do I got a 36 t sprocket and can only reach 28 mph I would think I should be able to reach more on flat ground but engine just seems to flatten out earlier than it should

 

[Mad man]

I'm running a yd 100, I have the dip reed kit and carb ported and polished the head. I had a vacuum leak between the reed block and the head close to day one. I removed the minimal amount of jb weld they tried to seal it to on the head where it was machined flat. Drilled and re tapped the 4 screws they installed initially to a larger size using Allen screws also putting a large worm clamp around the upper part of the head and block. Its still no vacuum leak so far!. Been running it coming up 2 years having a 2 piston I've replaced with 2 sets of rings. Honing it every time as well. Jetting is 150 on the main a 46 on the pilot a short expansion chamber boost bottle NGK b10 hs. It screams needle jet is set 2nd from the bottom. Plug reads chocolate brown . Lol. These things are a pain in the butt. Buy the rims and tires it'll save tons of grief.

 

[Karl Snarl]

The yds seem to be chuggers till broken in, in my exp. Once broken in and the jetting set, they are alright. I prefer the steel sleeve 100s though. My yd has been ran a few times, other than that it sits on the shelf till I want to find something for it to do. The steel sleeves got me hook line and sinker.