1985 Ezgo two stroke.

[philofab]

I had a 1985 EZGO two stroke come in three weeks ago with a slow start condition. It would crank over for 10-20 seconds with no power and then liven up. Customer put a tune up kit on before I got it.

First test I did was compression. Came back at 80 psi. Customer had never done top end, so I diagnosed it as needing a top end kit. Put the top end kit on and got 110psi. Replaced crank seals while engine was out. Motor had less power and ran worse. Next, I cleaned / inspected the carb. Throttle shaft tight and fuel bowl and jet were clean. Cleaned all of it anyways. Motor still down on power. Pulling choke or spraying starting fluid kills motor. At this point I'm thinking ignition.

Swapped out coil and pulsar for new units. No change. Was not able to locate a new ignitor, so I swapped out with a used but supposedly good unit.
Problem still persists.

Tested for clogged muffler. All baffles in muffler were broken and it didn't flow at all. Replaced with new unit. No change in performance.

I'm at a loss as to what to do now. At this point the customer is upset and I have a lot of hours I can't charge for. Any suggestions?

[shadowman]

did you take the 2 cables off from that bracket to the carb? if so when you put them on you didn,t cross them did you?................i have seen that happen several times.........also check the base gasket on fuel pump the thick plastic one make sure its not cracked, also isn,t there some sort of timing thingy where the front crank seal is? have you tried jacking rear up get it running and spray carb cleaner around the rear seal see if changes the way it runs? and spray all all around the base gasket make sure thats not going bad.........just a few ideas that don,t cost anything to try lasty have you tried running it with the exhaust off? i know you mentioned the baffles but how about outright with the mufflar off............................................

[Dave Box]

I had the same symptoms, slow to pick up and using the choke killed it. Turned out that I had a leak in the fuel pump diaphragm which cause fuel to leak down the orifice into the crankcase and make the engine run ultra rich. Eventually the leak turned into a split and flooded the crankcase causing fuel to leak from the exhaust manifold which is how I found the problem. Might be worth dismantling the pump and looking at the diaphragm.

[Pocono Country Boy]

Have you cleaned/replaced the fuel supply lines?

The 88 1/2 I picked up had the original lines and filters on it and they were pretty much plugged up. Motor made very little power and hadda be choked to keep it running. Replacing the fuel lines and filters as well as doing the carb made a world of difference.

[Dave Box]

First test I did was compression. Came back at 80 psi. Customer had never done top end, so I diagnosed it as needing a top end kit. Put the top end kit on and got 110psi.

You did get that piston in the right way round didn't you?

[philofab]

Originally Posted by Dave Box

I had the same symptoms, slow to pick up and using the choke killed it. Turned out that I had a leak in the fuel pump diaphragm which cause fuel to leak down the orifice into the crankcase and make the engine run ultra rich. Eventually the leak turned into a split and flooded the crankcase causing fuel to leak from the exhaust manifold which is how I found the problem. Might be worth dismantling the pump and looking at the diaphragm.

Originally Posted by Dave Box

First test I did was compression. Came back at 80 psi. Customer had never done top end, so I diagnosed it as needing a top end kit. Put the top end kit on and got 110psi.

You did get that piston in the right way round didn't you?

You were right on with a bad fuel pump diaphragm. That solved most of the problems. Not sure why I didn't think of it earlier. The piston is in the correct way.

Now it just seems to be a little bit of a tuning issue. It cuts out every once in a while, back fires after coasting, and seems a little down on power. I'm looking for vacuum leaks and swapping the original ignition components back in. The owner had me install a used igniter from an unknown source.

I appreciate the help!

[philofab]

What is the factory spec for compression on this engine?

[BrewCityMusic]

the backfiring after coasting could be that the spring is missing on the throttle cable (there is a small spring on the cable between the arm and the cable stop that ensures the butterfly closes completely when the throttle is released - without it the butterfly will sometimes not close correctly which allows fuel into the crankcase/cylinder when coasting with the ignition not firing, when you step on the throttle again and fire the plug, BAM you get detonation of that extra fuel) ... even if it doesn't always backfire, you're still getting extra fuel in the mix which can cause all kinds of poor running symptoms.

As to the vac leak, a really common spot is the top of the intake manifold (elbow) where the factory injector goes, you'd be surprised how many people remove the injector (which is good) and don't plug the hole where it dripped oil into the intake (which is bad). Also, if the compression is 130 (which is about 20lbs low for the 244) try the following: jack the rear up and get the cart running just above idle and hold it there, have someone spray WD40 or carb cleaner at the fan and at the rear shaft output, see if the RPM's increase at all - if they do, you've got a crank seal going bad (a common compression-thief)

[mvparcar]

my par car back fires like this. i have no springs on my carb,does anyone have a picture of the springs on a 88 par car?

[philofab]

Originally Posted by BrewCityMusic

the backfiring after coasting could be that the spring is missing on the throttle cable (there is a small spring on the cable between the arm and the cable stop that ensures the butterfly closes completely when the throttle is released - without it the butterfly will sometimes not close correctly which allows fuel into the crankcase/cylinder when coasting with the ignition not firing, when you step on the throttle again and fire the plug, BAM you get detonation of that extra fuel) ... even if it doesn't always backfire, you're still getting extra fuel in the mix which can cause all kinds of poor running symptoms.

As to the vac leak, a really common spot is the top of the intake manifold (elbow) where the factory injector goes, you'd be surprised how many people remove the injector (which is good) and don't plug the hole where it dripped oil into the intake (which is bad). Also, if the compression is 130 (which is about 20lbs low for the 244) try the following: jack the rear up and get the cart running just above idle and hold it there, have someone spray WD40 or carb cleaner at the fan and at the rear shaft output, see if the RPM's increase at all - if they do, you've got a crank seal going bad (a common compression-thief)

The crank seals are only a few days old but I may have blown one out with a backfire today. This cart has a factory oil injection still. The governor system has been removed and the throttle cable pushes rather than pulls directly on the carb. The carb is self has a spring that opens the butterfly rather than closes it. Compression as of today is 100psi. The fuel pump issue may have washed the cylinders down or lack of oil could have damaged it. I am going to pull the motor again once I get the other ten carts I'm backed up on out.