Won't start

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m38a1butch
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Won't start

Post by m38a1butch » Fri May 18, 2018 7:30 am

The mule has been running fine, starts right up.
Parked it 2 weeks a go.
Tried to start it today and it won't start.
Turns over fine - plenty of gas - looks like the carb is getting fuel - won't start
Where would be a reasonable place to start trouble shooting?

I suspect the magneto but don't know how to trouble shoot the magneto.
I will check to see if the plugs are sparking.
Last edited by m38a1butch on Fri May 18, 2018 8:28 am, edited 1 time in total.
USMC 1959 - 63
--------------------------
1952 USMC M38A1 MD delivered 9/52
1952 1/4 Ton M100 trailer delivered 9/52
1968 USMC M274A5 (now resides in the National Vietnam War Museum in Weatherford, TX -- RIP Francis)


markrdje
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Re: Won't start

Post by markrdje » Fri May 18, 2018 8:20 am

I'd check for spark/spark plugs
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muleman7
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Re: Won't start

Post by muleman7 » Fri May 18, 2018 4:22 pm

If you are able to crank the engine while standing at the right rear of the machine then remove the ignition lead from the right cylinder [standing at the rear looking towards the front] this is the easy plug to access. Hold the spring coil end of the ignition lead 1/2-1 inch away from the threaded end of the spark plug and crank the engine with the ignition switch ON. You should see a bright blue [violent] spark.

for an engine to fire and run you need:
Compression [for the mule it should be 110-125psi]
Ignition
Fuel
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artificer
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Re: Won't start

Post by artificer » Sat May 19, 2018 1:31 am

If these Mules have a magneto, clean & gap the points.
John GIBBINS Member Institute of Automotive Mechanical Engineers [Ret], ASE Master Medium/Heavy Truck & Auto Technician USA -2002 Licensed Motor Mech NSW MVIC 49593 Current 2015
TO DIAGNOSE, TROUBLESHOOT OR FAULT FIND ANY AUTO SYSTEM....
Understand how system parts interact with one another. GOOD parts can then be established & the NOT GOOD problem/s part/s isolated for repair or replacement.

Chuck W.
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Re: Won't start

Post by Chuck W. » Sun May 20, 2018 8:28 am

A very quick way I use to check the mag is to simply hook up a timing light. If the light is not flashing when you turn it over, the mag's not firing. If it's not firing, unplug the "kill" ground wire and try it again, if you have an electric hour meter, occasionally they will short internally and ground the mag.
What type mag do you have? If it's the electronic one, it's not repairable and you'll need to change over to the old style mag and wires. If it's the old style, it may take more that simply cleaning and adjusting the points, mule mags are bad to oxidize on the grounding surfaces inside the mag and must be torn down and cleaned. Do a search on the two mule forums, there are several threads I did on tear down and cleaning of the mag, I am not going to post them again.
Also, what plugs are you running? Should be Autolite 2223, which are no longer available. You can run the Autolite 2224, several are listed on e-bay now. If Champion XMD15 or 21, throw away and find some Autolite plugs. If you let your mule idle for long periods, any plug will carbon up and be very hard to start.

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m38a1butch
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Re: Won't start

Post by m38a1butch » Fri Jul 13, 2018 7:16 pm

I've never worked on a mule so this whole issue has been a learning experience for me. I learned how to correctly trouble shoot the fuel pump and it turned out to be the problem. Replaced the fuel pump (not easy) and now it's running fine. Of course now I have to drain the crankcase and replace the engine oil because there is fuel in the crankcase.
USMC 1959 - 63
--------------------------
1952 USMC M38A1 MD delivered 9/52
1952 1/4 Ton M100 trailer delivered 9/52
1968 USMC M274A5 (now resides in the National Vietnam War Museum in Weatherford, TX -- RIP Francis)


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