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rocks70

hot 720

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rocks70

my ac720 mowing tractor is 550 degrees at the cyl head and 260 at the oil filter.is this a normal temp? i think its way to hot mabe i should pull the engine and chech the fan.also it loses power when its that hot. any ideas guys?

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dentwizz

Depending on the part of the head measured, certain places can reach that much on an air cooled engine. I would however do a flow inspection of the cooling fins. A backshot of a compressed air gun to the outlet fins can sometimes pooof back a buildup enough to see or dislodge it. What throttle setting were you using at the time vs workload?

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John_in_Oxford

Hmm, a month back,discovered the 16hp Briggs in my old Sovereign wanted a new head gasket. It was losing power as it got hotter too.

Don't know why - while head was off, decided to reach inside the shroud, and pulled out 2-3 handfuls of mouse nesting!

Runs much gooder now.

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BLT
quote:Originally posted by rocks70

oil temp has me worried 260 seams way to hot


id="quote">
id="quote">If you get a handle on the high air flow temp, your oil temp might drop down to 200-210 deg F which isn't too bad on hot days. There is no way to check as that is something held close to the chest of air cooled engine people for good reason.

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blangkabel

I know it sounds like a lot of work but if you haven't had the engine out for awhile, I would pull it. You can only get so much debris out with the engine in the tractor. It might take an hour or two but would be well worth it. Once you pull it out you can give everything else the once over, and at the very least have a clean engine and a piece of mind.

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hurleyii
quote:Originally posted by dentwizz

High air cooled engine temps is one of the big reasons that you don't want to put junk oils in the engines.


id="quote">
id="quote">Amsoil, Amsoil, Amsoil!!!!

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phillobbezoo

I would agree with pulling the motor and clean all the cooling fins good, are all the covers on the engine and the belly cover in place, those covers are very important to keep things from over heating

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blangkabel

You mentioned that you use this tractor as a mower, if the belly pan is missing that will clog up everything under the hood. When I cut my grass with the 9020, 9 times out of ten there is debris over the oil cooler fins. when I finish cutting I always take compressed air and try to get all the debris out of fins and anywhere else I see it. That way the debris has less of a chance to collect and clog fins. On these engines the tins "heat shield" are very important for proper air flow/cooling. You may also want to check your head and see if it is warped. Are you using the correct spark plugs? I have heard these Onans are finicky is you don't use the correct plugs.

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720nut

I run H10's my concern with my 720 is the amount of air that's pushed out around the oil filter supposed to have a ring around it and been unable to locate one.

mine ran hot too but heads were leaking ,have since resurfaced heads and new gaskets. I ran for a while without cover on bottom made big difference when I put it back on.

like what was said about debris, I had a lot of old oil and dirt built up so a good cleaning would be inorder

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