New G9 Owner. A few troubleshooting questions

[BLSully]

Hi all,

I've owned this G9 for about 6 months now... It didn't run at all when I got it, so I went through the basics and got the motor running well enough for doing yardwork, running around to neighbor's, etc, but it's definitely got some nagging concerns.

(I was going to attach a picture, but looks like new members can't add links. Guess I will in a few days...)

It has almost always had a really bad tendency to stall out when getting on the gas hard. And hill climbing ability has gone from "marginal" to "basically won't". Not being previously very familiar with CVTs and their effect on engine operation, I always assumed it was the motor. Having done some reading this winter, it appears a weak or sticking driven clutch can manifest itself as problems that can make it seem like it's the motor. I ordered clutch puller tools yesterday and will clean/lube those up and see if that helps. The little white plastic pucks on mine are definitely worn, but not all the way through. The snap ring has NOT left it's perch.

I took the cover off the primary and I roughly understand "how" it works, but I'm not sure what to look for as far as wear on the primary weights/mechanism. It does seem to be leaving some grease on the inner bushing, so maybe the seals need to be refreshed at least.

Finally, I am not terribly good with electronics... I'm getting charge voltages as high as 17v. The regulator is definitely working, I think that indicates the regulator has a bad or iffy ground? Is that right? If so, I'm not sure how to go tracking that down. The cart has a newer battery in it (from previous owner). I added an LED light bar, and the voltage/charging issues seem to be making the light bar flicker occasionally. Only seems to happen at higher RPMS. Idling around or motor off, the flickering stops.

Depending on how my transmission debugging goes, I may just go with the Plowman G9 motor/clutch upgrades as I'd like to use it as a utility vehicle (tow yard trailers, etc). I find it very hard to believe golf carts would make a good snow plow, but seeing his videos, I'm tempted to investigate that route.


TLDR: How to analyze maintenance needs for primary clutch? Debugging over-charging voltage.

Thanks for any advice :)

-B

[Micjman]

Hey bud,

I'm kind of in the same boat as you (I've got a g9 engine in my taylor-dunn) and my was also not running 6 months ago.

I am sure you have already gone through some of these tests, etc. and I am honestly still a newbie at this stuff, but here is what I've learned to check in the past 6 months messing with mine:

1. When trying to climb the hill does pulling the choke help or hurt the performance?

2. The 10 MM bolt on your governor, is this set to stock or did you tighten it down?

3. Is the carb the original Mukuni, or is it aftermarket, and have you pulled it out and cleaned it really good?

4. There is filter inside the gas tank, did you replace this?

5. Does the airbox lid have all its rubber tie downs and gasket, is it on really good (any leak in air box or any vac. lines will reduce the pumping ability of the fuel pump.)

6. Where the carb connects to the engine there is black plastic spacer- if this gets cracked from age or over tightening the carb bolts, it losing power too.

7. They make torque spring for the secondary clutch, but if you are having trouble climbing hills, I think it more likely a gas-air-governor issue (your secondary clutch has this little plastic spacer things on it, if they are broken or worn that can be an issue, otherwise you should be able to see the movement of the primary if you jack up the rear end and watch the belt move and you spin the tires in forward).

8. check that the belt is not slipping (replace the primary drive belt if warn).

9. Mine works a bit better with a full tank of gas, I think it has to do with the added pressure this forces toward the pump.

10. I haven't done this myself, but know some have had good results changing to electric low psi fuel pumps, and others have bypassed the gov, or put the speed spring in it, or done the drill-out method.

Anyway, hope it works out for you, good to know there are other G9 people out there going through the same stuff as me.

[CP241]

First question, do you have the OEM carburetor or an ebay/amazon cheap Chinese "mokini"? If you have the latter, put the OEM one back on.

Make sure the plastic spacer between the carb and the head is not cracked. They crack *very* easily.

Make sure the air box lid is COMPLETELY sealed. Zip ties work well. If the lid leaks at all it will run lean and cause fits.

Check valve lash as well. Little adjustments can make a big difference.

What kind of compression numbers do you have?


The clutches will take a lot of abuse before showing any drivability issues. Grease the primary through the zirc fitting and same on the secondary. If the ramp buttons are worn by all means replace them but I dont think thats going to cause the issues you are saying. Sounds like engine related if it runs good but falls on its face when you floor it. You can confirm by putting the cart in "neutral" and watching the clutch operation. My first suspicion would be air leak causing it to fall lean on WOT.

What spark plug are you running?

As for the voltage thing, 17v is high but not alarming. I believe the ground wire at the regulator is the brown one. They have a tendency to burn up. Wouldnt hurt to double check to make sure thats good, but there is a good chance the regulator is just bad. After all it is nearly 30 years old...

[BLSully]

Hi, thanks for the responses.

1) The cart has it's original Mikuni carb.

2) I've sealed up the airbox tightly (using zip ties ;) ). The OE straps crumbled as soon as I took the lid off when I first got the cart.

3) I forget which spark plug it has, but it had good color last time I looked (right after I picked it up). I admit I haven't checked it since the performance started getting really bad.

4) I need to check compression. I'll go through the motor diagnostics a bit more thoroughly.

5) Was not aware the carb spacer was a problem point. I'll take that off and check for any cracks. Is there a common point where they get stressed and crack or does it seem to vary?

I'll gather some more data and get back.

Thanks again,
-B

[CP241]

Originally Posted by BLSully

Hi, thanks for the responses.

1) The cart has it's original Mikuni carb.

2) I've sealed up the airbox tightly (using zip ties ;) ). The OE straps crumbled as soon as I took the lid off when I first got the cart.

3) I forget which spark plug it has, but it had good color last time I looked (right after I picked it up). I admit I haven't checked it since the performance started getting really bad.

4) I need to check compression. I'll go through the motor diagnostics a bit more thoroughly.

5) Was not aware the carb spacer was a problem point. I'll take that off and check for any cracks. Is there a common point where they get stressed and crack or does it seem to vary?

I'll gather some more data and get back.

Thanks again,
-B

Give us some compression numbers. That will tell a lot.

HAve you checked valve lash? Also makes a big difference.

The plastic carb spacer cracks if you tighten the carb too much, usually near the studs. It's just a splined stud holding into the plastic, go a 1/4 turn too far and it breaks. every time. I wish someone would make an aluminum one and a gasket set for it, I think they'd sell great. Stupid things are $20 each for the plastic ones. Just pull the carb off, and remove the spacer (2 philips screws) and look at it in the light. If it's cracked, it'll be pretty obvious.

[BLSully]

Well.... Guess I'm rebuilding this thing. Valves were in spec. Carb spacer looks good. Exhaust valve maybe a touch loose. Compression was a dismal 120psi, 130 with some oil added. Guess I'll be seeing what the machine shop charges to do a top end...

[CP241]

Dont use a local machine shop or you will be rebuilding it again in a year or so. Pull the head and look at the cylinder. If theres no major scoring you might be able to get away with a hone and new rings. Worth a shot anyway, as long as it's not shaped like a bell. Worst case, call plowmans. You get what you pay for. And with plowmans what you'll get will be a beast.

My G9 was smoking like a train but had 165-170 compression. I checked my cylinder and it was straight so injust ran a hone through to deglaze it and a new set of rings. Figured since I already had the parts may as well give it a shot. It's still running perfectly. Maybe I got lucky but if it needs rebuilt again I'll be deciding between the big 26hp or whatever it is Vegas carts kit. Or a plowman motor.

[jclark138]

CP241 sounds like he’s been down the same road - Plowman’s will be my next change on my Yamaha - not just ‘cause I’m from Michigan. . . . Our EZGO got a VC 460.
It doesn’t stop!

[CP241]

Originally Posted by jclark138

CP241 sounds like he’s been down the same road - Plowman’s will be my next change on my Yamaha - not just ‘cause I’m from Michigan. . . . Our EZGO got a VC 460.
It doesn’t stop!

When it comes to stuff breaking/going bad, I think I've been down every road there is to go down with my G9. I've got all the parts to rebuild the king pins (actually have had them for about 6 months...) but that's the only thing on this cart I have not touched... yet.

[BLSully]

I'll give him a call and see what I'm in for. The clone route sounds like fun, but I don't need a rocket-ship. My cart's primary uses are bombing around the subdivision (rural 2-3 acre lots), and occasional yard work duties. A fresh motor with whatever secret sauce Plowman does will probably suit me just fine... I have motorcycles if I feel the need for speed =0P