Keeps flooding out. I've tried EVERYTHING

[Rcarlson]

Hello all and thank you for allowing me to join the forum. I have a 1984 ezgo marathon with the 2pg engine. I completely rebuilt the engine a couple of years ago. All new everything. It ran like a champ until recently. It will sort of start and barely run. Keeps flooding out. Power is so low it won't move the cart. I checked compression with a good tester and it has 120 psi. I replaced the carburetor. I replaced the fuel pump. I disconnected the exhaust to verify it's not clogged. I sprayed carb cleaner around crank seals, I could not tell any noticeable change. Cart had good spark, but I wanted to do the HEI conversion. Changed everything over to HEI and still the same problem. I swapped fuel pump again, cleaned brand new carb and checked float level, etc. Still won't run. If i choke it at all it completely floods and stops firing. I have replaced the NGK plug. I drained all the old gas and mixed up some new, 91 octane with 128:1. I pulled the Reed valves and inspected them. They're fine.
I looked inside the crankcase while the Reed valves were off to verify the crankcase had not filled with fuel. I am stumped. I can usually make anything run but this thing is kicking my butt. Can bad crank seals cause this problem? Or a leaking cylinder base gasket? I have oily residue around the exhaust port. Any help is tremendously appreciated.

[LukeL]

Is it a cheap Chinese carb? I chased problems on a 3PG for a couple weeks until I tried cleaning my OEM carb and using the gaskets from the Chinese one.

[cart around]

Any kind of an air leak will cause a 2 stroke to not run.
Since it is flooding, I would have leaned towards a ripped diaphragm in the fuel pump. You say it's new, so we eliminate the pump.

It could be seals, or a leaking gasket. It could also be timing. Getting spark doesn't mean it's at the right time.
You did the HEI mod, so try switching the red, and blue wires from the pulsar first. A really long shot could be a slipped timing plate on the pulsar, or a sheared woodruff key on the flywheel. Highly unlikely, but still possible. You could check those while changing the crankshaft seals.

What kind of carb cleaner did you use to test the seals? Not all carb cleaner is flammable. It's also not a 100% reliable test.
Pull the fuel line off, and check for a healthy spurt of gas while cranking.

Here is a manual to use.

[Rcarlson]

Carb is a new mikuni, same as what my cart already had on it. I did try reversing pulsar wires, made no difference. I have pulled the fuel line and made sure it was pumping good. I will pull the flywheel and check timing, key, and pulsar next. I don't know what kind of carb cleaner I used, I already threw it away. I got it at Menards. I did squirt some starting fluid in the carb while cranking and it stopped firing altogether. Flooded it out.

[Rcarlson]

Can anyone explain how a leaking crankshaft seal would cause an engine to flood? I understand it causing a lean condition, but not flooding.

[Rcarlson]

LukeL nailed it. It looks like the carb I bought was a knockoff. The reason I changed the carb in the first place was because the mixture screw had fallen out. I guess the locknut had worked loose. I robbed the screw and lock nut off the knockoff and put on my original carb and it runs great again.

[LukeL]

Originally Posted by Rcarlson

LukeL nailed it. It looks like the carb I bought was a knockoff. The reason I changed the carb in the first place was because the mixture screw had fallen out. I guess the locknut had worked loose. I robbed the screw and lock nut off the knockoff and put on my original carb and it runs great again.

Ha ha. I’ve seen it happen a couple times now. Glad it’s going again!

[CP241]

Originally Posted by Rcarlson

LukeL nailed it. It looks like the carb I bought was a knockoff. The reason I changed the carb in the first place was because the mixture screw had fallen out. I guess the locknut had worked loose. I robbed the screw and lock nut off the knockoff and put on my original carb and it runs great again.

That's about the only thing those chinese carbs are good for... robbing some of the smaller parts, plastic linkage attachment pieces, gaskets, etc. for the real carb. I've done that before more than once :)