G9 clutch adjustment

[G9ty]

Can you adjust the clutch on a Yamaha G9 golf cart? If so how do you do it?

[sho305]

Not really, the best adjustment is to clean and lube both of them so they actually work like they did when new.

You can get a kit for the secondary clutch its a bigger spring and a spacer as the big spring will break the C clip behind it. You can also get a cut sheave for the secondary it gives a lower initial gear, it helps for towing and takeoff, climbing. If your sheave is worn it will not shift right, it will be dished in the center. I'd recommend you get a new cut one.

Far as the primary you might as well buy a new aftermarket clutch that is adjustable. I can tell you if you make sure the tension cable is adjusted right (at end of generator) and motor mounts are good, the clutches are not that worn out, and are clean and lubed, that it should run pretty well and have reasonable power an speed. A lot of these carts don't get service, the stuff is dirty or worn out and people think that is normal...its not. Also if the belt is worn to 1" wide it is junk, and really junk if you have a lifted cart a new belt works better.

You can also adjust the backshifting on the secondary if you have a stock spring, or get a larger stock spring for a work cart/limo model from yamaha. If you wind the spring with more preload it will stay at higher rpm at partial throttle. This gives more response, takes more gas, makes more noise. You still have 9hp so its debatable if it is worth it, but you can wind it up and it may be nicer if you trail ride all the time. If you wind it hard it will run at full throttle rpm all the time no matter how hard you step on it.

[G9ty]

Do you have to take them off to clean?
How do you clean them? Thanks for the help.

[spriddle]

Pull the cover off, usually has philiphead screws holding it on and then clean it out. You'll probably find old grease piled up on one area of the cover.

[sho305]

Take the cover off and I used brake clean spray the first time, it has stayed clean since. Then you check the parts make sure the weights and pins/links are all working ok and not about to break off. I lubed those with light chain lube I like super lube. I put just a drop on the pins they swing on. Then put a couple shots of grease in the zerk, make sure to clean any extra that comes out anywhere. After than only one pump maybe twice a year depending on miles you run it. Mine will drag the belt at idle when it needs a pump. If you put more it will fill the cover with grease and can trash the belt. The secondary (rear) clutch you clean the shaft inside the spring and most have a grease fitting on the back side to grease that moving sheave. Check the ramps back there and the plastic shoes that ride on them. Ramps need to be smooth and free of dirt/etc., leave them dry. If no grease fitting then you can spray some lithium grease (spray can) on the shaft inside the spring. Best to take the belt off when you do this so you can move each clutch sheave by hand to check things out and get the lube moving into it. If belt is 1" wide it needs to be replaced. Check alum sheaves for wear they get dished in from the belt it will not work as well, eventually it can't get the belt to the top anymore. Eventually they wear holes in the sheaves but steel halves don't do that.

You can do it all in the cart, you may have to pull the battery or airbox to get better access, the rear body comes off pretty easy too a few bolts under the seat and couple under bagwell.

[spriddle]

Dang, Sho... were going to put you in charge of creating all the new service manuals buddy.

[dcdoc45]

I pulled my driven sheave, and replaced the spring with a yamahauler spring. I cleaned everything up and put the grease in the zerk, but I would like to preload the spring as you suggested, just not sure how to do that. A little more detailed explanation please?

[sho305]

Excepting the G1, you can preload the secondary STOCK springs with the ends on them. What this does is controls back shifting. There are three holes in the sheave and four in the helix, they are offset so each will give a different degree of preload when the ramps engage...that way you can change it little by little if you really needed to. ABC and 1234 if you can read the markings, the spring can wear them off. G9 takes a B4 setting with 60 degrees of clockwise preload. That means you put the spring in those holes on each side, then turn it 60 degrees (1/6th of a turn or about 2 o'clock) and push it in to engage the ramps. Note you then have to get the outer sheave with the key in correctly on the shaft at the same time here, hold it on, get the nut on to secure it (43ft lbs), to hold the whole thing together. With a stock spring it is not that bad, aftermarket have to be strapped down usually.

Interesting the manual says to put 3 pumps of grease in the primary with the cover off checking for excess grease. Says secondary spring should be 100mm long or it is out of spec. (3.94")

Anyway, what happens with the secondary is if you gas on the cart the engine torque makes the moving sheave climb up the ramps and down shifts the trans. At some point the weights in the primary overcome and it shifts up so RPM does not go too high. When you drive at light throttle the ramps have little pressure on them so it is easier for the belt to drop down in, the primary "wins" and it shifts to a higher gear and RPM go down. Only the spring length holds the secondary closed at that time. (or the strength/wire diameter of the spring, the yamahauler is supposed to be a little stronger) The preload is how far you wound the spring, that pressure keeps the ramps forced together just like engine torque does. So if you wind the preload much harder then the ramps are under pressure all the time and it runs in 'low gear' all the time. It will run at the same RPM as if you had it on the floor all the time, it will not lose RPM at light throttle and shift out. It will make noise and eat gas lol. However it will be snappy, and air cooling will work nicer. So for some offroad running you could wind it a little tighter than factory. It will not change how it runs at full throttle, it will not make it have more power. This can help a lifted cart deal with larger tires better.

So the preload affects how the ramps work, and more pressure means they stay at high rpm position more of the time. What I found is it was exactly the same at full throttle, but at part throttle with lots of preload it revs hard all the time more like a utv. Problem is stock cart engine does not need to rev like that.

Once you have the secondary off it will come back off pretty easy, until it is on there for a while. I pulled mine off about 5 times one day and tried different settings and for my use went stock.

An aftermarket spring ignores the preload all together, and uses a way stronger spring to keep the secondary closed with only static pressure.

[aw1026]

Does this also apply to the G29?

[cgtech]

In general, no. Most had the team axle with no tangs.