Does a GX240 Honda carb have mixing adjustments? It floods after running for 2-3 minutes then fouls the plug and stops. Thanks, Mike in SC

Engine model number?

Check the crankcase oil is not contaminated with fuel.

Inspect the sparkplug. If its oil fouled (black sticky wet deposits), do a cylinder leak down test.

If plug is oil fouled, you could replace the plug and it will run but it will likely oil foul in an hour or so or even minutes... it would confirm rings are shot and the leakdown test not necessary, but be sure fuel is not getting into crankcase.

It's also possible the decompression mechanism has failed. It will start with the extra fuel from priming then die. Could also be impulse air to fuel pump... model number?

Double check air fuel mix screw settings for new carb... again model number?

Typical for any carburetor is 1 1/4 to 1 1/2 turns (out). These are just rough settings to get the saw running. Remove chain, turn idle throttle speed screw in to increase idle rpms so its less likely to stall. Follow mfg instructions for starting.

Once running, adjust low speed mix and allow a couple minutes to warm. Then re-adjust low speed and lower idle rpms by turning out idle throttle speed screw. Then with throttle wide open adjust high speed mix. If saw hesitates from idle to full throttle, open low speed mix 1/8 turn and readjust high speed mix.

If saw doesn't fire in 3 or 4 pulls remove plug. If plug is dry no fuel, if wet either no spark or idle mix to rich (or fuel metering may be fouled).

To have success using starter fluid as a diagnostic you will need to remove the air filter cover and element. Then with choke open make a short (1 second) burst of starter fluid directly into the carburetor throat. (There is no need to saturate the intake with starter fluid... it is bad practice.) Promptly pull starter cord no more than 3 times. If you have compression and proper spark, it will fire and run for 1-3 seconds and stop as it will have expended the available fuel (starter fluid).

If it doesn't fire, repeat procedure. If still doesn't fire, likely no spark or plug is fouled. Promptly remove spark plug and check that plug is dry. Then check it has proper gap and you have spark. A wet plug will imply it is flooded and a flooded engine will not fire even with starter fluid.

If it does fire, then the likely problem is no fuel or water in fuel. Drain fuel bowl and some fuel (1/2 pint) from tank (just open fuel shutoff valve with carb bowl drain open) into a clear glass jar, let set for a minute and check for visible water line. If water visible, drain tank and refill with fresh fuel (use a clean EMPTY fuel container go to filling station and get 2 gal. fresh). If no water, then likely carburetor is fouled and will need service.

Try a differant plug and have the carbs adjusted and synchronized.

mix is too weak, not sure if you have a carb or electronic ignition so if carb, probably needs a clean and new filters, if electronic get it checked

Adjust your idle. Sounds as if it is turned down to low. The reason the plugs are fowling is due to a flooding issue. Rebuild carb and make certain the floats are set properly. If the idle is opened up too much, it's allowing too much fuel to draw in and fouling the plugs. Also, I wld check and replace any gaskets and seals that may be worn out or leaky. Good luck!

i would try adjusting your carb sounds like u might not be getting enough fuel or to much and flooding it out also try a new spark plug couldnt hurt

Basics to check:
1) Spark plug - brown or dark brown - OK
a) is it carbon or fuel fouled
b) is there spark

2) Muffler remove for inspection
a) exhaust screen clean or plugged
b) inspect cylinder wall/piston as the flywheel is slowly rotated
3) Check cylinder compression


Overfuel or 'rich' condition
Basics to check:
1) Spark plug - brown or dark brown - OK
a) is it carbon or fuel fouled
b) is there spark

2) Muffler remove for inspection
a) exhaust screen clean or plugged
b) inspect cylinder wall/piston as the flywheel is slowly rotated
3) Check Air filter for fuel saturation
4) Allow engine to run for 5 minutes remove to excess fuel from muffler
5) Fuel mixture ratio: Make sure the oil mix is per your manufactures recommendations
6) If after the above the engine is still smoking and blubbering:
Adjust carb mixture screws to a 'less rich' setting
*NOTE: only move mixture screws 1/8 of a turn at a time,
and try operation before any more adjustment

I’m happy to assist further over the phone at https://www.6ya.com/expert/rolandw_c013176d62ee17ae

I know this one FOR SURE!!! Killed me for days-- my mileage was HORRIBLE, and the #2 manifold was ICE cold while the other three were nice and warm. A multiple step solution ultimately got it going again, and I was thrilled finally.

Yes, the plug is fouling out---too much fuel. Idle mixture screw is useless for this issue, return to factory spot and later set Idle proper after the carb float has been adjusted. Gotta take the carbs off for this, although not completely apart. Get the group of 4 out (lotsa tricks to do this easily, otherwise, get ready for some frustrations in taking them off--lotsa hair pulling, etc.

The adjustment of the floats in the individual carb needs to be set exact. 1/2mm high or 1/2mm too low=noticeable difference either super lean or super rich.

To confirm the fouling, after riding for 10 minutes or so, just reach down and feel that exhaust manifold. It'll be ice cold with it's pushing all the fuel past this carb. My The other firing cylinders will have these manifolds warm/hot to the touch. When this occurs, pop the plug out--you'll get a lot of gas since the fuel is leaking right down in the cylinder at an amazing rate (far faster than the running carbs consume fuel. You're oil may also be tainted now with good bit of gas mixed in.

Hi again,

Hard starting could be caused by:

• vacuum leak (specially since you can not adjust idle lower). Was the original 2T oil injector to the carb plugged?
• 2T oil pooling at the bottom/bowl of the carb (specially since you are using pre-mix);
• the sparkplugs fouls fast/easily. You can try changing the plugs in the morning before you start.

Imagine the scenario of the original arrangement of the carb & 2T oil (not pre-mix); on initial start/early morning, gasoline would be drawn in first without much 2T. This ensures that the engine fires. When it is already running, that would be the only time the oil pump will work and therefore inject the 2T to the carb to mix with the fuel drawn inside the combustion chamber. With pre-mix, the first gasoline used (inside the carb's bowl) has already oil mixed.

Good luck and thank you for using FixYa.