Re: Mule 610 problems
could be float sticking. Or float valve not sealing properly. How is it used? Lots of idle time? Short duration trips at low speeds? Run wide open full speed on the governor for a few minutes down a road or trail?
As I've said before, the engine is a generator engine. It's designed to run full throttle all the time. In the Mules, they commonly get run at lower speeds for short distances and a lot of them sit and idle for extended periods. Both of these conditions cause vapors to build up in the crankcase. Sometimes there's enough humidity in the air to show up as milky oil. The cure is to run it harder, like the engine was designed to do in the first place. I generally recommend running low range on the governor from time to time, for a few minutes at a time, this helps to get the engine oil temperature up which boils off any vapors and condensation.
Also I just recently ran into a fuel pump that had a diaphragm that was allowing fuel to get into the crankcase, so that could be an issue.
Also-when the 610's first came out, we were advised that some people would haul them backwards on the trailer. Meaning back it up onto the trailer. If you look at the air intake, it's at the top of the roll bar in the back side of it. What was happening was at highway speeds, the 65+ MPH air would actually pressurize the roll bar, which is directly connected to the air box and eventually the carburetor-which caused engine flooding. Solution, cover the intake or haul it the other (right?) direction.
Also engine oil overfilling from the get go. Must be checked on flat surface. And the stick should be inserted in the proper direction. It can be put in backwards but it doesn't want to be (has to be kind of forced in). In most cases, filling the crankcase until it's ONLY between the checkered markings on the stick is sufficient. It doesn't always need to be at the top line-which is the "high" mark. The bottom line is the "low" mark. In between is perfectly acceptable.
Also valve adjustment can cause issues. Intake valve gets a little tight and causes more reversion in the intake tract, which doesn't help matters any.
Those are a couple random thoughts on this situation, for what they're worth.