2006 Mule 610 wants to die on hills

[Gonzo]

I have a problem maybe similar to the one below on the forum that like him is driving me crazy. Mule seems to run fine except sometimes when I am climbing a hill it wants to die out just about the time I reach the top. Yes the tank is full when this happens. I have drained the tank, putting new fuel in and fuel additive, new fuel filter, spark plug, checked wiring and even had a motorcycle carburator friend disassemble and clean the carburator (he had his own shop, never seen anyone so particular about cleanliness), also checked to make sure the gas cap vent worked. The mule has about 425 hours on it and I have never adjusted the valves so maybe that is it. Would valves cause an issue like this? I checked the fuel pump to make sure it was working, seemed to be, did not replace. I have a factory manual I payed dearly for and done everything per the manual. I have no way to get the mule to a shop, live in the Appalachian mountains beyond the boonies and really love my mule but it needs to be dependable. Breaking down could mean a very long walk home or worse. I keep her close by the house these days but don't want to. Any help would be greatly appreciated.

[KAWMECH]

SOUNDS LIKE YOU HAVE DONE EVERYTHING CORRECT. I WOULD ABSOLUTRLY BE CHECKING THE VALVE CLEARANCE, KAW SUGGEST EVERY 250 HRS. CHECKING THEM.

[Gonzo]

Yes I am overdue. I have adjusted valves on older inline 6 engines. Had to do them hot so it was always a race to get them done before things cooled off. Will break out the manual and see how to do it. Thanks for the reply!