mule idle problem

[rzr09]

i have 4 4000 mules i take care of at work and can not get them to stop stalling. i have adjusted the valves, cleaned the fuel pump screen, replaced spark plugs, air filter, can't check fuel pressure but i am getting enough volume from the line. the dealer said i should get 1.7oz or more in 3 seconds. i am getting close to 3oz. the check eng light is not on either. if anyone has been able to figure this out i'd sure appreciate some help.

[Brennan11]

We have a 3010 Mule that will idle perfectly, but will falter when the throttle is opened. It will run up a bit and then do nothing as long as the throttle is open. It is about three years old but has low hours (42). I expected to find stale gasoline and gunk in the float bowl, fuel filter, and carbureter bowl. Everything was clean, the float is OK, and the electric fuel pump has good pressure and volume. The carb has a barrel for each of the two cylinders and a separate main and idle jet for each cylinder. I took out the four threaded jets that are removable and found them clean. The vehicle will run sufficiently to move the vehicle on level ground if the mixture is enriched a bit with the choke out. I was completely convinced that the problem is fuel related, but after taking the carbureter apart for the second time and checking everything else I am stumped. Occasionally when running it enriched, I hear a knocking sound as if detonation is occuring, leading me to suspect the ignition module. I know of a tractor that would idle but die with opened throttle as the increased pressure shut the spark off. To bring this thought in line with the observed behavior I reasoned that a richer mixture is easier to light. I hope that someone has experience with these things.

[mrOkie]

Have you pulled the pilot circuit air mixture screws and the pilot jets and checked to see if you can blow carb cleaner thru the circuit from where it gets air on top of the carb to the tiny holes in the throttle chamber? I suppose that you have a service manual? There is a manual for the 2 cylinder liquid cooled engines online just do a Google search for Kawasaki FD671D/FD711D FD750D There is a service manual for the Kawasaki industrial engines there. It is downloadable FREE! It has a good explanation of the way the two barrel carb works, The pilot circuit is shown, there may be some differences in various models of the application

[cheddarpecker]

You have to drill the plugs on top of the carb. Be careful, as if you go too far, you'll cheese the screw heads. If you've cleaned the carb and it's back on, just drill the plugs, run a wood screw in the hole, and pop it out with a pair of side cutters. Likely, all you need to do at this point is to back them out a bit until it idles high and even. Adjust adle after.

[mrOkie]

Thanks cheddarpecker,

The plugs on my 3010 Mule have small holes in the brass plugs, I didn't have to pull them as I was able to get the carb circuits all cleaned with Berryman B-12 carb cleaner in the aerosol can and by using a small guitar string to pass thru the circuits. I put the carb back on, got the idle speed set ok and the Mule runs good and idles nice and smooth. here is a picture of the top of the carb:

I intend to order the industrial version of the pilot screws with the EPA plastic limiters (23013-2063 is the number that I have) that can be adjusted without having to drill out any plugs

[cheddarpecker]

It's easy enough to step up the holes and pop them out with any suitable self tapping screw. It's also just as easy to booger up the threads above the screws with the wrong driver, but I prefer instant access, without having to pop limiters off, or buying different screws. Under the plugs, a flat blade screwdriver will turn them just fine, so long as it isn't too wide for the recess. I have modified drivers for such purposes. I also don't like anyone telling me I can only turn an adjustment so much. There's a certain sense of pride involved in waving my finger at them.

[Will]

I regularly work on small engines of all sizes from weed eaters, lawn tractors, motorcycles, up through auto engines. Here is what I have discovered and it may be a solution to your idling problem. The small fuel galleries supplying fuel to the jet are very prone to varnishing closed because of their small size. It doesn't take long for varnish to form in a machine that is idle - especially in a seasonal or seldom used engine. When this happens the idle jetting is the first to foul and if you have any question try this. The engine will likely run only with the choke pulled because it needs a richer mixture. This is proof that the fuel is insufficient without the choke on. Choking the engine restricts air flow thus balancing the air/fuel mixture to allow the motor to run. To fix this I never remove the carb, but rather use healthy doses of Stabil gas additive to the fuel at about 6 oz per gallon and run that through the engine. That dosage can be reduced as the process proceeds. How many tanks will it take to get back normal fuel flow depends on how plugged the gallery is. Just continue to run with the choke on to keep the fuel flowing and the more you run it the quicker it will clean out. I also use Lucas Upper Cylinder additive to help this process. Some folks prefer Marvel Mystery oil and Seafoam in the fuel, and I guess that works okay too, but I haven't used it enough to have the same confidence in it as I do in Stabil. Proof that the carb is getting cleaned is when you can open the throttle more and need less choke. The ideal is to be able to open the throttle quickly and not have the engine cough or hesitate. I'm pretty positive that if you do this you will clean out the carb. Now, once you have that done, do your prevention and always add whatever brand additive you like to the fuel and for this I prefer the Lucas product. That cleans the carb and also helps unstick the compression rings. People who live in a hot climate run into this type fuel related problem because of the faster evaporation of the fuel. And no, don't blame it on old gas....i've run engines on 2 yo old gas with no problem. I take motors that won't run and "fix" them easily with this method if it's a fuel problem.

Good Luck

Will

[4 dog knight]

Check out a product called FuelMedics. It works like the Stabil...but also works really well on oxygenated/ethanol based fuels.

[robin]

ATVworks.com has a Mule carb rebuild kit for 39.95. Here is a link to their site: http://www.atvworks.com/search.asp?pg=1&stext=cr319&sprice=&stype=&scat=

[mrOkie]

ATVworks.com has a Mule carb rebuild kit for 39.95. Here is a link to their site: http://www.atvworks.com/search.asp?pg=1&stext=cr319&sprice=&stype=&scat=

Thanks for the info, that seems to be all the parts needed for the usual rebuild. My problem seems to be rust particles that get thru the filters, (really small particles) from a rusty fuel tank. I have been down with some health problems and haven't got to work on the Mule, we are using the electric EZGO instead. I still have the 4 aftermarket wheels and Swamp Boss tires stored in the garage that I need to sell.

[newt]

Do you have a pitcher of the tires+wheels

[mrOkie]

Do you have a pitcher of the tires+wheels

yes check out this Topic: [Mule stuff for sale?]