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Back Cylinder running rich


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I have just purchased a 07 3010 Mule. It has high hours at 1900 but has been well taken care of. It seems to run well but just a bit weak. Every now and then I hear a clinging sound that may be a ignition spark to ground but I can't seem to find it. It will not do it when I'm looking. Also the back plug is showing its rich. It is black in no time where the front is a lite brown. 

I did find it had the wrong plugs so I changed them, but no help. 

As I have just got this I was wondering what do I need to look at as far as simple mods or weak points. 

Thanks for your help

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rear coil packs are know to go bad on these models,  i have one of the 3010 myself, the carbs are a problem child with the enthol gas mix, i had a float problem that led to washing my cylinders out, had to re-hone and re-ring  the motor, check your compression on both cyl.  also watch out for blockage on the air filter and the frame tube, had a old hornets nest that fell down the tubing and blocked the air filter, the 3010 are good machines but do have there quirks, if your having a idle problem there is a great write up on that, and the 3010 do hate cold weather, 

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Coil has been replaced then the fuel pump goes out. I replaced it with a Mr Gasket fuel pump. Its running great now but I do have a question.

I modified the governor by drilling the holes and set the RPM's at 3000 full throttle in neutral. But when I took it out for a spin it ran the same speed of 22 mph. The motor has about 2000 hours but runs great and doesn't smoke. I'll do a compression test today and see where that's at. Could it be the motor is too weak to run up faster under load? 

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 don't touch the governor on these motors, not a good thing .... they go boom easy.....

On 4/26/2020 at 6:02 PM, GDS said:

The rear coil is bad. I hope to pick one up tomorrow. 

 Then it died altogether turned out to be the fuel relay. I’m not sure what it’s suppose to be doing. I jump it out for the moment  

if its still the factory pump  its not the relay it the pump the pumps on these suck really bad its pressure draw system, and the point in the pump wear out all the time


as for the fuel pump you will need to do a regulator on it if not you can flood the motor the gas will push past the float,


here is the link to set idle on the mule carb it works ....


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I put the governor back where it was but don't understand going boom when the sticker on the frame show max power at 3600 rpm's. Normally max will be below red line. But being it didn't seem to help overall speed, no need to bump it up. I haven't done a compression check yet as my gauge must be held in place.  

As far as the fuel pump it is running great with out a regulator, no flooding. The Mr Gasket 42S max pressure is 3.5 pounds. Now I don't know what the specs on the original pump was but most float type needle and seats can easily hold 3.5 psi. 

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its not a flooding issue ....... I have hydro locked the motor with that fuel pump

.the mr gasket fuel pump does work great i my self have used them on tractors and my mule ,   couple of dont's do's with that fuel pump, depending on how you have it wired in \, don't let it run while the motor is not running, the float will leak down with constant pressure, the float seat does wear after time and the floats do go bad, use only factory parts for carb rebuild the after market one suck



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you will not be able to run the mr gasket pump off the fuel relay, i tried and could never get it to supply and that relay is $$$$  as for pressure IRC started off on the 2 setting  think Im running 2lb pressure , I set it by keeping it low and when i was losing power bumped it up a little at a time,  as i said b4 keep checking you oil level , you can wash the cylinders really fast  



also the gauge and fittings







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I guess ill have to read up on the carb. Is it not vented? If so too much fuel would run out the vent. Gas washing the cylinder should only be able if you oversized the jet. The jet plus maybe needle adjustment should set up max fuel in the cylinder. Pressure in the bowl should not effect how much fuel goes in the cylinder unless it is way off. I could see more trouble if this was a diaphragm type carb but it's not, it's a float type. 

As I understand the fuel relay, when the ignitor is on/running, the relay is on. No mater what pump you use, 12 volts is 12 volts. I did however order after market relay for 16 bucks. I'll run with out one before I spend 90 bucks for something I really don't need. I don't know a reason to have the ignition on and not actually start the engine.

As of now it seems to be running great, a little cold natured to start. Guessing if it was running rich/ gas washing the cylinder it would start up much easier, as if the choke is closed.   fr

With all that said I could be wrong, I was once. lol Feel free to correct me. The biggest thing I have learned in life is you are never always correct and you can always learn something. 

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