Cart Running Rich

[dyereance]

I just bought a 2006 EZGO MPT1200. It had sat for awhile and the carb needed to be cleaned out. I got an IPB for the cart and noticed it had the wrong air cleaner. It had the rectangular one on it and the tabs on top to open it up were right up against the metal frame that the seat rests on. According to the IPB, it cam with the round air filter assembly. I got the rectangular one off, removed the carb, cleaned it and put it back on. I started it up without the air cleaner and it fired right up and ran great. Well, the round air filter assy is no longer made so I got a used assembly with a new air filter and when I connect the rubber hose from the air filter to the carb, it runs OK for about 100 yards and then eventually dies. I pulled the plugs and both are black from running rich. I take the rubber hose off the carb and it runs great! I did a compression test and both cylinders are at 150PSI. The carb was not bad inside and it doesn't look like there's much adjustability to it, so I'm kind of stumped. I've seen a lot of people mention adjusting the valves but not sure that would help seeing how the engine runs great with no air filter. And I also verified that there isn't any obstructions in the filter assembly. Any ideas?

[golfcartg]

I see a lot of people suggest adjusting the valves when they run into issues like this, but honestly, valve adjustments are only necessary in very specific conditions. I commend you for holding off on that and taking the more thoughtful approach of cleaning the original carburetor, most people just slap on a cheap aftermarket one. That tells me you’re on the right track.

Given that you’re still running into problems, I’d recommend sending that carburetor to a lawn mower or small engine shop for a sonic cleaning for a more thorough process than what you can typically do at home and could make a big difference.

When reinstalling the carb, replace all the intake gaskets to look to see that everything’s sealed properly. Drain the fuel tank completely and fill it up with fresh fuel. Gasoline that’s been sitting for a while can cause more problems than we sometimes realize. Pull the fuel line at the carburetor and crank the engine, you should see a steady pulse of fuel coming out.

These engines really do need a proper sealed intake system to run well and any slight difference in the air cleaner setup can throw off that delicate balance. Between that and a sonic cleaned carburetor you should be well on your way.

If your spark plugs are black that indeed means it’s getting too much fuel and not enough air. The fact that it runs better without the air filter hose connected further supports this. Adjusting the carburetor’s rich/lean screw can help balance that out. On the top of your carburetor look for the mixture air/fuel screw. Start the engine and let it warm up to operating temperature. Locate the screw, turning it clockwise will make the mixture leaner (less fuel, more air), and counterclockwise will make it richer (more fuel, less air). Start by turning it slowly about a 1/8th turn clockwise. Run the engine for about 1 to 2 hours of driving time for the spark plugs to show their true color, transitioning from black to a light brown or tan (not white) indicates the proper air fuel mixture.

[dyereance]

Thanks for the info. The previous owner took care of draining the tank and it only has had non-ethanol fuel since. When I got it, it was running lean. (The choke had to be slightly pulled out for it to run and then when driving it you had to manipulate the choke in order for it to keep running.) Then it quit all together and I found the float was stuck closed due to debris in the bowl. When I attempted to take the carb off is when I found out the air cleaner assembly was incorrect. While cleaning the carb, I replaced all the fuel lines and filter. Is the air/fuel mixture screw the one on the top with the black plastic cap? I looked it up on the IPB and it shows it but doesn't say what it is. If that is the correct one, then it's about 1/2 way through it's travel as shown in the picture.

[Michael Eddie]

I can definitely relate to what you’re going through. I had a brand new carb from EZGO and after sitting for about six months, it gummed up just enough to need the choke half open to run properly. It doesn't take long for today's fuels to cause that varnish buildup even with nonethanol fuel. Like mentioned earlier, I’ve got a sonic cleaning planned with a friend who has the equipment. Thats the screw. If you’re still running into issues after adjusting, I agree a good sonic clean should get things back on track I think