New spring or power package?

[rando]

I am looking at power or torque kits. You can get just the spring and spacer or a bigger kit with a machined sheave. The bigger kit comes at a much bigger price. My question is it worth the big bucks or would just spring and spacer be fine?

[sho305]

The machined sheave gives a lower first gear, that gives more power at roughly 0-4mph or something. The spring keeps rpm up more but is not fun to install. I would recommend you make sure both clutches are clean/lubed/working right and you have a newish belt on it before putting in a kit if you are at all unsure. A lot of carts don't get cared for and if the clutches are not up to par you lose a lot of power. On the other hand I really don't like the secondary springs, I ground my ramps and some other mods to get mine to pull boats out of a lake and I'm happy with it. Well I was, now going to a 16hp clone and then its not a problem. I just put one in with only a cut sheave and its impressive compared to stock plus my engine is pretty tired.

[rando]

Thanks sho for the input. Just didn’t know if the bang of the full kit is worth the bucks to get it. The plans are to put on bigger wheels & tires and I have read a lot of posts about it taking more power off the line. Also would like to do easy to mod trail riding. The cart dealer put a new clutch on the motor and new belt but the rear half of the system is original. Don’t know how much wear and tear it’s had.
What 16 hp motor did you install? Sounds really cool. The more I read about carts the more I want to do to mine! Addicting!!

[sho305]

Well a spring kit may do more harm with no lift, its the higher gearing of the tall tires that kill your torque. I have 22s on mine. Be careful some kits kill your top speed too. I would lift it first. All you have to do with the secondary is check a few things, like check the pads and ramps on the back side make sure the plastic pads are good and ramps are smooth (not ground up from running with no pads). Make sure the moving sheave (the inner one) is not flopping around on the shaft because the center bushing is trashed, it should not tilt on the shaft. Squirt a pump maybe two of grease in the fitting near ramps. Clean any excess grease. Before you grease clean the shaft inside the spring if you need to, I use brake cleaner you can blast it with water/pressure washer and let dry or run dry. Check the aluminum sheaves for wear the belt wears into them and dishes the inside out, eventually they can wear holes into the sheaves. This is from lots of dust/dirt. If they get dished bad they may not shift that well. You should be able to spin the tire on gravel and dirt with stock tires no problem, spin like crazy if you turn right and floor it, or on grass.

With more power the clutch setup does not need to look for power as much, most people take the power springs out when they put a larger engine in. I used a 16hp clone, check out the clone forum. I posted photos of it in my 'clone specs' thread, and others have posted check out 'thenewguy's thread about his jeep. There are some other good clone threads. Home depot sells them now mine is from carrollstream and harbor freight sells some of them. They made hondas (in China) a while back then honda left, so they make these copies of hondas most parts will fit for a honda. The 16/15hp is a bored and stoked 13hp gx390. Some call it 16hp home depot says 15. The cheaper one with no alternator or electric start is only $250. Stock they don't rev high as a v twin so you don't get more top speed, but they can be modded.

[Dave in VA]

After mine was lifted, I took it to a cart guy in Wytheville because I didn't want to screw it up He replaced the worn sheave on the secondary, added a spacer and used the stock spring. For mild and semi-moderate trail riding it seems to do fine. He also replaced the rollers in the primary.

I've been thinking about Plowmans Hot Set-up with their Performance Pipe in the springtime. Can't justify getting a BB.

[sho305]

I could not justify a BB either, but since I can fabricate the mounts and whatever....once I found out I could put a clone in for less than a rebuilt and nearly for what just rebuild parts cost for the engine itself...well now its a no brainer to put a 16hp in. Then after I rode it, well there is no question. It runs just like stock but with twice the power roughly. Sure its a pain to install, have no doubt about that. We have around 500 total into it and the dealer here said 650 for a rebuilt if I bring the bare engine in and trade. But a rebuilt has 9.4hp or whatever it is. Now you can get the engine for 250 and adapter was 50, I could do that for under 400 total with all the exhaust and airbox stuff, mount parts, everything. The one I did we used electric start so we can start it either way, or change it in the future. If you can do it, I'd tell anyone not to waste money on other mods when you can double the power like this. I can toss a rooster of dirt with 22s now its a riot, wish I could of got some video but it kept raining the last few times I went there.

He jumped the gun here but look how his cart keeps getting smaller while he is on the gas.

YouTube - G9 16hp pull

YouTube - G9 16hp pull

[rando]

Thanks again sho for the info. I had things to do today but will look at the secondary sheaves tomorrow. I know there is a lot dust on everything because the roads at the campground are mostly dirt. I don’t remember the sheaves being worn but I know what to look for now. I do know it has never spun the tires not even in grass. It was the campground dog this summer but mostly because the governor was way out of adjustment. The 10mm nut was backed out so far I had to turn it in ¾” before the cable had any tension at all. This winter I will cover the basics with the body work, paint and get some good tires on it. Maybe next year the big block.

[rando]

Looked at the secondary and it looks good. The ramps are ok, the shaft under the spring was clean and no play in the sheave bushing. The belt however was 3/8" down from the top and the sheave halves were together at the bottom. I watched DOOmsman's video many times and the belt was always at the top before rpms. I was told the belt was new in May when we got the cart. Could the sheaves be worn that much? Also I could not pull the sheaves apart by pulling on the belt, is that normal?

[sho305]

The sheave has to rotate up the ramp as you pull the belt, you may have to pull pretty hard on it and it will come up. If you have a spring kit in there it may not. Measure the belt 1" wide is the yamaha wear limit, the more it wears the lower into the secondary it will sit. New is 1 3/16" wide. At 1" that will hurt a lifted cart but non lifted its not that bad, you want to change before 1" is reached on a lifted cart.

Governor what is that? LOL Mine is long gone that is the first thing I took off it. Make sure the throttle cable at the pedal is adjusted to pull the carb all the way open yet still not pull it open at all before the starter activates. Adjusted and even with the governor all the way in it should spin the tire in poor traction conditions with stock tires....if the clutches are working right and it is running right. You may have to try a little by turning or something. A sharp right turn and only a driver should always create spinning on dirt or grass at full throttle.

This belt is not new:

YouTube - Yamaha golf cart G9 clutches

YouTube - Yamaha golf cart G9 clutches

Here is how my old G9 runs with 22s:

YouTube - Spin on G9.wmv

YouTube - Spin on G9.wmv

It normally GPS at 28mph down this drive on dirt and 30 on pavement.