one cylinder missing?

[jink11]

I have an older model ez-go (80's maybe) with a Robins 4-stroke. It is running rough and weak, not much speed or power. Seems and sounds like it is only running one cylinder or misfiring. I exhausted my abilities on it to no avail and took it to the shop. Mechanic has been stumped so far too. Between us we've checked compression, changed the coil and changed the timing belt. His next guess is maybe the pulsar coil under the fly-wheel.

Anyone have any ideas? Thanks!

Robert

[crash12888]

The coil fires both side at the same time, two fires per cycle so it won't likely be a pulse coil issue with these symtoms.
While it is running use a shielded pair of pliers or thick glove and pull one plug wire off, does the sound change, put it back on and try the other one, any change?
If you have one bad hole the sound/RPMs won't change when you pull the bad side off.
When you find the bad side pull the valve cover and check that side of the cam, look for wiped or missing lobe. A compression test won't catch it if it is the exhaust lobe.

I also had a hair puller one time that ended up being a bad plug wire boot. Didn't find it until I threw a blanket over it and saw the spark arcing to ground on the plug base.

[jink11]

Thanks for the suggestions. My mechanic replaced the valves and gasket and such. Cart runs better but, is not right still. It runs perfectly at lower rpms like just above idle speed. But, as soon as you give it more throttle it starts to sputter and bog out. He even put a rebuilt motor in the cart and it still acted the same. He said something about the problem maybe being the governor in the rear end. Seems like a fuel/air problem maybe. Checked the fuel pump and it is pumping plenty of gas. Any more ideas would be greatly appreciated.

[crash12888]

Did he use your carb on the other motor?
Sounds like the high speed circuit of the carb is clogged and starving for fuel.
Playing with the choke help or hurt any?

[jink11]

Not sure, I'll ask him tomorrow. Choking, even just a little, just chokes it out completely. So if I take carb off and clean it real good it might help? Or just buy new carb?

[crash12888]

Unless you got money to throw away clean it.
You don't even need a kit, teardown, clean, blow out and reassemble.

[jink11]

I certainly don't have throw away money. I will pull it and clean it tomorrow. Thanks for the help. I noticed you're from Chesterfield co. Va.....I was born and raised there. How is my old hometown these days?

[crash12888]

Originally Posted by jink11

I certainly don't have throw away money. I will pull it and clean it tomorrow. Thanks for the help. I noticed you're from Chesterfield co. Va.....I was born and raised there. How is my old hometown these days?

Like everywhere else, growing and loosing it's personal charm where everyone knows everyone.

[worqhors]

Originally Posted by jink11

Thanks for the suggestions. My mechanic replaced the valves and gasket and such. Cart runs better but, is not right still. It runs perfectly at lower rpms like just above idle speed. But, as soon as you give it more throttle it starts to sputter and bog out. He even put a rebuilt motor in the cart and it still acted the same. He said something about the problem maybe being the governor in the rear end. Seems like a fuel/air problem maybe. Checked the fuel pump and it is pumping plenty of gas. Any more ideas would be greatly appreciated.

Possibly a faulty ignitor. Borrow a kniown good ignitor.