Machined Sheave

[LURCH]

Does changing the Sheave along with the spring help that much more, or will the spring do just as much. I really dont know what a 28 degree sheave does over stock. Please Help.

[sho305]

Depends on what you mean, a machined (secondary) sheave for a yami is when they cut the inside down so the sheaves go closer together. That pushes the belt out the top a little, and gives a lower initial low gear. It does work I have one on a clone 16 and it will fast idle at like 2mph, it gains rpm on takeoff faster because of the lower 'gear'. It also pulls the belt deeper into the primary at idle, could cause dragging issue with belt but this cart does not seem to mind. It rips up steep hills.

28 degree is usually the helix angle, the ramps that shift on that sheave or the hub...which ever one does not have the shoes on it. That controls back shifting, or how much it shifts down on high demand/load. This is so when you ride up a hill it shifts back and allows more rpm. the belt torque rotates the sheave on the ramps to shift it with high load of pulling/hill/takeoff. So it depends I forget what way the degrees are measured and what they have stock. A steeper ramp will shift less keeping the rpm more the same under heavy or light load, while a longer less steep ramp will rotate easier under torque and shift more with load change. IIRC the ezgo often swap to different angle with bigblocks. I cut the ramps down on my G9 and it gained rpm when towing, I only did the first part of the ramp so over about 5mph it is stock. It only does it at larger throttle, it was done to get a boat out of a lake. The spring preloads the ramps to adjust how they work, a stock spring you can rotate more or less to control partial throttle rpm and make it back shift going downhill. But it keeps the rpm up all the time, takes more gas and makes more noise, but would cool it more. You can tighten it up some and give it more snap since it adjusts about anywhere in between. You change what holes the spring is in to vary it. Aftermarket springs do not preload they just force it apart with a lot more force, that clamps the belt more and keeps it from shifting out as soon, keeps rpm up more.

The clone cart with the cut sheave I ran with the stock engine it also helped that, but always had a stock spring in it. I don't prefer aftermarket springs I think it better to run an aftermarket clutch you can adjust...but some people swear by the springs. One that is too strong can kill your top speed so be careful what you get. They are hard to put on and you need the spacer on the yamaha behind the clutch it will break the snapring. Most take them out if they put a larger engine in.

[EC-Cartman]

Very, very well put sho

[LURCH]

I ended up going with the Plowman's kit, both sheaves, spring, spacer and belt. I dont have the cart together yet since its a complete rebuild but should be ready in a couple of weeks. Thanks for your help.

[Dave in VA]

Originally Posted by LURCH

I ended up going with the Plowman's kit, both sheaves, spring, spacer and belt. I dont have the cart together yet since its a complete rebuild but should be ready in a couple of weeks. Thanks for your help.

Did you get any other goodies from Plowmans? I've been thinking about their Hot set-up and the posi.

[LURCH]

I wanted to, just not enough money. I did get the air filter and jets.