Power Mods for a G1 ?

[sho305]

I don't recall it being any worse than the secondary. If the clutch is screwed, either one, the rpm will be off or too low usually. This will not be the case going fast with no governor it shifts out and it revs up higher. Though the G1 does have a power peak at lower rpm than most think. If it bogs, rpm are quite low, that tends to be a clutch issue. But if it revs some and you still have no power then look at the motor. I would check the exhaust first for restriction. Also check for intake leaks though it should idle poor with those. One cart here I shoved a rod up the exhaust and it took off.

[RCDART]

Exhaust is clear, nothing is slipping the engine just doesn't pull good going up hills and rpms are low. I think if it was allowed to rev a little higher it would be fine. Thanks.

[RCDART]

Golf Cart 001.jpgOk got the front clutch apart and blew the dust out of the cover with the weights but the outer sheave did not come off looks like it's rusted on the splined shaft..can i tap on it to break it loose or no?

[sho305]

Originally Posted by RCDART

Attachment 33445Ok got the front clutch apart and blew the dust out of the cover with the weights but the outer sheave did not come off looks like it's rusted on the splined shaft..can i tap on it to break it loose or no?

I don't even remember how they come apart anymore, but pretty sure only the inner sheave stays on any of them. Certainly the outer sheave moves if it don't that is for sure a major problem. Be horrendously careful with a hammer around one of those. I'd say put some penetrating spray on it, give it a minute or more, and try to tap on the hub next to it if possible. You can't touch the sheave part its very weak. You might try to wedge some 2x4 or other wood down at the bottom of the sheaves to force them apart, if you get you right, it should slide off? Try to be gentle whatever you do, to start. It depends if it is bottomed out or not, if not you might tap it in to break loose with a socket or something that lays across the part at the shaft/splines. Also lube those weights where they move before you put it together and otherwise check it out but don't think you can get new parts for those anymore a shame too. Not the smoothest but for our use they were the best.

You could also try to heat the hub a little maybe just a propane torch might help it move if above fails. Unless you have a puller for it of course. Someone might have some parts but yamaha does not make them anymore.

[RCDART]

I got it, a snap ring held it on. I could push the sheave in an 1/8" from the snap ring before i felt any spring tension. Then when i got it apart it looks like the spring was cut with side cuts to make it shorter, looks like a golf course didn't want the tires spinning maybe and shortened it but here's a pic of the spring. Spring on the left is out of my clutch and the white one on the right is out of a snowmobile clutch that i'm gonna try in there. Thanks again.Golf Cart 2001.jpg

[RCDART]

Ok the white spring won't work so i shimmed the old one about 3/16" and it had no affect, cart still wants to move immediatly when you hit the gas and bogs until the rpm's come up then runs great.

[RCDART]

Found a different spring that had one more coil than the stock one, now it will just barely run without trying to move but i still have a bog. I've tried adjusting the low speed screw but it don't help. Any ideas? Thanks.

[sho305]

The length of the spring determines how high is revs before engagement, the strength sort of determines how it shifts stronger is more rpm. It should be right for rpm, unless something else is wrong the spring needs to be longer. If damaged you may have to shim it more. It should be sprung open at rest.

The complaint about them was they rev up some and jerk forward. Of course that was often because nobody serviced them. Yamaha made the new clutch that engages at 100rpm with no spring more or less and it can't jerk no matter what.

Actually the spring might be so old it lost some spring. You might have to stretch it longer that could be the problem.

[RCDART]

I'll try a shim then. Is that causing it to bog so bad because it's engaging before the rpm's are high enough? Thanks.

[sho305]

Originally Posted by RCDART

I'll try a shim then. Is that causing it to bog so bad because it's engaging before the rpm's are high enough? Thanks.

It certainly could, but its always hard to tell with CVT. If its not shifting right it will bog at too low of a rpm to make power, on the other hand if the engine is not making normal power the clutches are no longer tuned to work right. G1 didn't have to run that fast to make power, compared to a sled for example, but it should be a quite fast idle before it moves. You could also stretch the secondary spring it might be old and compressed. If it is too weak the belt will suck into the secondary under big load and low speed, like a hill at low speed. When that happens it acts like you pulled the choke nearly, it bogs and stops, blah, at very low rpm. If you looked at it the belt would be in the secondary instead of right at the top like it should be for lowest gearing. Sometimes you can sand the moving secondary sheave with real fine paper even steel wool (don't get the stuff in the bushing) and it grips more, then will run the ramps down better to keep low gear.

All that said you only have to look at the clutch, and with a spring you don't even need a belt on it. It should be open, when it hits the rpm you want it to start to engage it will start to close. Otherwise the spring is too short or very weak/out of spec. The belt pulling in the secondary should only happen under big load and no speed. On a sled it might take off at 4K rpm, sure maybe it starts to pull in at 3600, but not grab the belt with force until 4K. Some sleds it would snap in hard at 4K. Usually a trail or stock setup was smoother. The stock G1 did engage not much above idle, but a shim would make a difference. I used to turn right and smoke the tire in circles on a paved parking lot. I could lean on my left knee sitting on cart, hold the brake, and spin the right tire on pavement. Must be the left brake was stronger. Given the cart had plenty of little things done to it.