EZ-GO Golf Cart running poorly

I have a 4 stroke gas powered EZ-GO Golf Cart that is running poorly. When the motor is cool, it runs and is driveable, but still does not seem like the rpm is as high as it used to be nor does it seem like it is as powerful. If I drive it continually (like going to check on the hay field)it seems like it gets weaker and weaker as the motor warms up, to the point that it will barely move. Then, if I stop and try to start again, the motor just turns over and chugs...but then is driveable again when the motor cools off somewhat.

I pulled the plugs and they are dry, but there is a lot of black carbon on them. Thought maybe I had a weak spark so I swapped coils with another running cart that I have, but this did not fix the problem.

I haven"t had time to troubleshoot any more. Anyone have suggestions on what could be causing this problem. I really need to get this fixed as I use this cart ALL the time!

Thanks,
Tim

Black plugs can indicate a rich mixture. Is this a fuel injected or carb engine? Basic engine manufacturer- Tecumseh, Kohler, Kawasaki, Honda? Couple possibles- likely a choke on or partially on/stuck or automatic choke pulloff broke disconnected if electric. That would give the slower when warmed and hard start symptom. Happens with small engines on lawn tractors. Look for a vacuum pull off hose off or broke or a electric solenoid wire broke or off. Fuel injector models- cold start/warm running sensor disabled/broke gives same rich mix when warm as needed for cold start- again same symptoms as choke on. Gas tank venting clogged is another possible low power after running- doesn"t get fouled plugs usually though. Have you checked cooling fins or radiator for dust and junk?- relatively common problem found by the small engine shops- causes over heating, tight piston clearance and low power, hard start when warm. Stuck spark advance in retarded start position may give simlar low power when warm and some plug fouling. Check your engine oil- are you running some winter weight leftover 5-20? 30 weight racing oil is a common recommendation for summer use now, the 15-40 off road diesel or motorcycle oil is good alterative on many and may be recommended by engine maker. Too light oil would have some over heating possible and oil getting by rings would cause some plug fouling. Worn rings may be a possibility- fouling would be symptom and low power, but the fail to warm start while good cold start is not a main symptom of worn rings with low compression. RN

I don't know the age of your cart, but the last gasoline cart I owned had a Robin engine( or Robinaire). Sounds like your might be running rich.
Butch

check the air filter--could cause rich condition---then check all the electrical connections. bright tight and shiny, poor ground that heats up can cause.

Tim,

This is way out in left field but here it is anyway. I have a Craftsman riding lawn mower. It works well when it's cool, but the longer I run it, the slower it goes and the more the engine bogs down. I also noticed that the oil in the engine is near boiling when it bogs down completely.


The problem turned out to be a bad axle bearing in the differential. When the engine was really bogged down, I tried pushing the mower and the right side wheel would just skid along on the ground. When it cooled, it turned more easily.

Like I said, this is way out in left field, but you might check out how easily the cart rolls when it is in that "bogged-down" state.

Tom in TN

Golf carts are not designed for dusty fields, you should modify the air intake system to draw air through an overhead stack,very dusty in the engine compartment.
My EZ-GO has a Robin engine which now needs an overhaul due to very low compression.My use was identical to yours.

The plant I work at has probably two dozen or more EZ go's with Robin engines. Some are used as carts some as assault vehicles (joking). I have worked on them all and there are a few "problem children" that always run rich no matter what. When they come in for maintenance, the crankcase is usually full to the top with gassy oil. I have replaced carbs, tuned, filters etc. My BIL works at a golf course and he claims they need valve adjust frequently, but I have not noticed this. So I guess I can offer no real advice other than the obvious.

I would definitely check the valve adjustment and the compression far as that goes... I have one a few others I keep up... The coils are know to go bad (even a known good'n)... Check the spark with a spark checker... If it pops the checker its not ignition plain and simple if it does not I would install a coil for a quick check... I use a GM coil like in the pix with a resistor... Its a common coil and can get the number if need B ( I have a stash of used ones)

Spark checker get one... Go no go gauge no guessing :wink: Don't be a fool are get fooled get one....




Coil
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Mine has always run on the lean side,,, just never went into the carb to clean it out When mine gets low on gas it runs like its real lean,,, I clean the engine, blow the air filter out, fill it with fuel and it runs like a new one till it gets real low on gas again... must be sum'n to do with the fuel pick up but if a little gas takes care of it and it does I not mess'n with it....

The engines are as simple as it gets to work on,,, parts are extremely high :twisted: I have complexly rebuilt 3 of'em a piece of cake.... The engine repair manual is as good a manual as you can find... I down loaded mine FREE... [/img]

On my ezgo 2 cycle it acted somewhat like that and I replaced the fuel pump. Im not sure what the 4 cycles use for a fuel pump.

That is a classic sign of an ezgo 4 stroke that needs the valves adjusted. Set them at .004 both intake and exhaust. Its easy to do, just pull the valve cover and roll the motor over by hand to get the valves in the proper position. After that see if it still runs rich, then adjust the carb if needed.

My old EZGO would start fine and after about 100 yards lose power and stop then a few minutes later run fine for maybe 20 yards then same thing. I replaced the solenoid but did not solve the problem. Next I tested the fuel pump and it was fine. If I used the choke 1/2 it would keep running. Almost took the carb off then remembered that I got some bad gas that clogged the brass bolt in the bottom of the float bowl on a power washer that I had.

Solution: I pulled the fuel line off the after the pump and sprayed a bunch of gumout in the tube. Then drove around the yard with the choke pulled until it passed the gumout. Now it runs perfect again. I also put some more stabil in the fuel plus gumout carb cleaning gas treatment.