JD LX279 Engine Trouble...

[runnin14]

I've got a 99 LX279 (17hp liquid cooled Kaw - 48in - gator blades) that has been relatively well taken care of - yet has been used quite a bit...no idea of hours as that year did not have an hour meter on 'em.
She'll run like a top for 45 minutes or so and then out of nowhere it will start cutting out - losing power - even though the mower is at full throttle - the engine will be going in and out and about low to medium throttle (no smokin'). The mower will never fully recover from this "type of behavior" unless you let it "cool" down for a bit then it is fine for another 30 minutes or so...
Needless to say I have not done this too many times - afraid that I will be damaging the engine - I check the air screen on a "as I mow" basis, and I have blown the radiator out the best I could (you can't truely get to the back side of it without taking everything apart)....I have flushed the radiator - changing the antifreeze - changed spark plugs -....as you can tell I'm thinking that it is just getting to hot (yet the tell tale light is not coming on)...have not replaced the radiator cap yet...the only thing left to replace..........

Anyone with any ideas as I am quickly running out of 'em

[marthanmike1959]

I had the same problem with my jd 345 20 horse kawi i hope your problem was as simple as mine.Have you checked your battery mine had a cell going bad and would shut down stupid me let the water in battery get low then it completely shut down.Could be something eletrical

[runnin14]

I will definitely check it - but I did put a new one on the mower at the start of spring (may have a bad battery but i hope not - got it at autozone so it does has warranty)....

[Bill Kapaun]

What happens if you loosen the fuel cap? Might be a clogged cap vent?

[runnin14]

headin out -----
talked with a few people today and the consensus is that it may be a coil for one of the spark plugs going bad....JD place said they will heat up - get too hot causing the engine to cut in and out....I can test it by unhooking one at a time (it has two) if it dies - then the one hooked up is bad (duh) - unhook one and it keeps runnin and the engine noise stays the same - bingo - that is my problem - or so they say...we'll see...
update later