Restricting speed?

[GREENI3]

Every time I get to 37 mph, it sort of cuts the power/acceleration (the engine stays on though) for a second then returns back to normal, but keeps doing the same thing every time it gets to 37 mph. Sort of like a juddering motion.

I know it's a 50cc moped and your first assumptions are probably a cdi restriction or something along those lines, but it's only started happening recently.

Before, it would go as fast as it could. It managed 45 mph down a hill, but if I tried going down that same hill now, it will go no further than 37.

Any ideas what it might be?

Thanks,

[Redoko]

[cb1rocket]

it appears you have done the CDI but not the washer in the variator....?

[Nope.]

The AY50 has three restrictions:

1) The exhaust (Washers in the manifold)
2) The Washer in the variator
3) A rev limiter in the CDI

It sounds to me like you have hit the Rev limiter in the CDI. You'll need to replace it with a third party one. Malossi do one that works well.
____________________
Former: Derbi GP1 50, Sachs XTC 125, Suzuki GSXR 400 GK73A, Kawasaki ZX7R, Suzuki DR250, Yamaha RD350
Current: 2011 Yamaha XT660Z Ténéré, 2003 Yamaha YZR-R1 5PW (In Build), 2009 Kawasaki ZZR1400

[GREENI3]