One of the 1st things I did was put on a 16 toother (so easy to do, how could I not). I didn't get out much before the switch so I can't really comment on speeds before hand, but with the 16, I get around 65-70 mpg and comfortably hit 60. Over that it starts to get really buzzy and high revved.

Wondering about getting a 1 tooth smaller rear sprocket to take down the revs a bit more at the top end. From what I can tell, there still seems to be enough of power left, I'm just starting to run out of revs. over 65ish.

Insights?

Quick Question
 

So I've changed out the OEM 15T to the 16T, the problem is that I don't feel the difference.

I still have to change it at the same speed, if I wait for it to reach around 15, then the engine is revving way too high.

can anyone help me with this problem?

Please and Thank You.

Where you really gain with the 16t sprocket is on the higher end. There is a barely noticable advantage in 1st and 2nd but at higher cruising speeds, you can comfortably travel at 60 to 65 without the engine screaming for mercy. The big advantage to the 16t is that it will help prolong the life of the engine if you are constantly travelling at the higher speeds by reducing the rpms.

I also wouldn't drop the rear sprocket any with the 16t front. It may seem like it could handle it but these bikes make very little torque stick. Losing a tooth on the rear is just going to further reduce torque and the rpm difference will be negligible imo.

I left original 15 tooth sprocket in place. These engines are not pressure lubricated (10 psi oil pump just squirts oil on the moving parts). All crank shaft bearings are roller bearings. This type engines are designed more to run at higher rpm rather than higher loads. As proven by many there is no top speed gain to be had, just weaker acceleration netting performance loss. The only reason to to the swap is to limit vibrations at cruising speed. But vibrations are minimal any way (thanks to balance shaft).