Yamaha G2 Primary Clutch comes in too early

[TKO22]

First post here. (Actually I wrote the whole post out once after logging in, and when I tried to submit, it went to the login page and when I did, it displayed the home screen. This time I'll copy it to the clipboard before trying to submit!)

I recently bought a lifted G2 with a few mods... Airbox removed and replaced with a UNI. Governor removed. It has a header with a small motorcycle type muffler welded on. I got the cart cheap as the unsupported header/muffler broke the exhaust bolts off and the previous owner gave up on it. I drilled/tapped the head for larger bolts and welded up a support for the muffler.

This is my second gas golf cart, but first one with any modifications to it.

I'm not new to CVT clutches as I raced F500 cars with high horsepower snowmobile engines with very adjustable primary/secondary clutches. We would tune them for the track conditions, cornering and longest straightaway.

The cart now starts, runs and idles perfectly after some valve lash adjustments, rejetting, etc.

BUT it is almost undrivable in tight areas or if backing into parking spots or my trailer or garage.

I've had the primary cover off of it and it seems like the outer sheave is very easy to slide in and out on the shaft. I puzzled for a while on how to remove weight from the links to try to get the clutch to come in later.

We used to fiddle with the secondary spring preload some to try to keep the rpm a bit higher in the corners, but I have to think the drivability issue has to be in the primary.

Any ideas from ya'll would be appreciated. Our club limits speeds to 10 mph, but this thing will do 30. Speed isn't a concern ... drivability is key for me.

Best regards,

Mike T.

G2a.jpg

[cgtech]

Well, it's not supposed to idle at all, so that's first problem (supposed to start with pedal press). The idle speed is probably too high.

[TKO22]

Not supposed to, but can. Idle speed is fine. My club car will idle stationary with a smooth acceleration. This Yamaha comes in real hard, too soon.

I’ll get it figured out.

Regards,

Mike T.

Edited for spelling.

[slonomo]

I agree with cgtech, the golf cart engine / clutch setup is supposed to engage right away, it's how the cart starts moving. Engagement rpm is probably like 1400 rpm or so if I had to guess. They were made for the golf course, very low speed vehicles.

If the clutch engages at 1400 rpm, try and set your idle speed to 1200. It might take some work on the carb to do that, as they weren't really designed to idle. But it can be done.

With that said, if there is something wrong with the clutch, that's a different issue. Maybe that clutch has a ton of hours on it? Might be time for a replacement.

Now if you were to do an engine swap with a lawn and garden type engine and you used a 780 clutch, your engine would idle at 1100-1200 rpm and your primary would engage at say 1800 rpm. That gives some wiggle room. Then you could expect to have the cart sit and idle without taking off.

[raydhd]

I drove my G 14 with the stock engine and key start for most of the 6 years I used the stock engine. The stock engine idles nicely and revs up smoothly. I could stomp the throttle and still the take off was smooth.

[slonomo]

Originally Posted by raydhd

I drove my G 14 with the stock engine and key start for most of the 6 years I used the stock engine. The stock engine idles nicely and revs up smoothly. I could stomp the throttle and still the take off was smooth.

Maybe I'm interpreting his description wrong? He says it's "undrivable" and "won't idle". Doesn't say if it's key switch or starter/gen, so I'm assuming it's factory stuff. With a starter/gen carts usually aren't setup to "idle".

[raydhd]

Basically they don't idle because the stop start switch cuts the engine when you lift. Both my cart the start stop switch was eliminated and very few adjustments were needed for a nice idle. That even includes the HD cart with it's stock 2 stroke engine. Maybe I did misunderstand his question. When he spoke of idling I assumed the stop start switch was eliminated. IMHO the stop start switch with a high idle can make tight parking less than ideal. Hopefully the OP will clarify that point

[TKO22]

To clarify...

The start/stop switch is not eliminated from this cart ... yet.

I’ll put my tach on it and see what the idle speed is, but from my experience building Briggs 4-stroke engines for karts, I suppose it’s in the 1K area.

It idles fine with the rear wheels off the ground.

I’m comparing the clutch operation to the 98-99ish club car I have that starts and idles and has a very smooth clutch engagement and is very “drivable” in tight quarters... just like they should. If the rental carts at the golf course drove like this G2, there’d be a bunch of crashes!

This G2 will scoot along on starter only, and what is the starter rpm?... maybe 400-500?

I have the body off of it now, so will revisit the clutch issue later in the week.

Have a safe Memorial Day!

Mike T.

[TKO22]

I got the clutch sorted out and it’s very drivable in tight places now. I also did drop the idle adjustment as low as I could and still idle. Step on the gas and the engine starts and smoothly accelerates. I also set up the driven clutch to stay in a bit lower gear by increasing the spring preload.

THEN... today came home with a terrific 1990 G2 (barn find) for $200. Absolutely filthy, 4 flat tires, but all there. A mouse or rat had dragged a package of sunflower seeds into the engine area, and there were seed shells everywhere, but no chewed wires. Planned to use a few body parts and the roof for my lifted ‘86 G2 and part out the rest of it... but... Replaced the cracked fuel line from the pump to carb. Disassembled the carb and cleaned it thoroughly, cleaned the spark plug, added my boat battery, checked the oil and diff, added a gal. of fresh gas w/seafoam ... and it started right up and drove great. Rust free chassis too!

[TKO22]

Here’s the lifted Yamaha G2. I’ve changed the steering wheel since this pict was taken...

Note the back rests... before recovering, I reduced the foam thickness by half. I’m 6’4”, and was sitting too far forward with the thicker foam, and was killing my back. Fits me perfectly now, and can cruise around for as long as I want without being hunched over the steering wheel.