[charleswrivers]

Cam... all day long. A12-A14 depending on whether you still want a high top speed.

I run a A13, has great low end and MASSIVE midrange to help me climb. It accelerates to 25 very rapidly then slowly pulls to 30 in the first 100 yards or so. Haven't done a top speed run because going more than 30 isn't important. I need the power for hills, getting through deep mud and hauling lots of weight. While it seems to run kind of higher RPMs at low speed compared to stock, it doesn't have the power to keep pulling at high speed so it kind of settles at comfortable medium at speed. I'm running a 1500 torque spring, stock clutch springs, 12g sliders, unifilter, afternarket muffler, rejetted carb.

Also, your clutch springs being 2000s may be causing a lot of engaging/disengaging if your doing a lot of on/off throttle. I do a lot of tooling around at low speed so it wouldn't match with my driving style. I'd be slipping the clutch constantly. If your smelling the clutch/seeing smoke come from your CVT vent, it's a possibility. I recently replaced my belt and noticed the new belt was substantially tighter than the old one, despite then being the same size and might be worth inspecting.

I had 13g rollers stock and went with 12g sliders as a single mod so I could feel just the one change. I thought it helped hold me in low better than the roller by a large amount. I don't know if a slider would give superior performance to a roller given the same weight. Some things I read made it sound like it could improve both low and high end.

In recap, A12-14 cam, possibly open your CVT and check the clutch and belt condition. Read your plug again. Im a touch lean running a 130 near sea level. Cams are cheap and easy compared to the other stuff you mentioned. Try that definitely before you go further.