k321 dies under load ..

[psheph43 0]

I have a 1982 c 145 auto with the 14 horse k321 Kohler... The tractor hhashad the plow on it for the past 8 months and had ran perfect .. I put the deck on a couple weeks ago and cut grass for about 5 min and the engine died and would not start ... Found that it was not getting fuel .. Replaced fuel pump and got it running again .. Now every time I engage the PTO I can hear the blades run and I can start cutting and within one minute the motor starts to bogg down and shake really bad and then cut its self off .. I can normally get it started again with out an issue but as soon as I engage the PTO it dose the same thing ... I have replaced all ignition comments and checked pullys on deck to make sure they are free .. Any help is greatly appreciated! This thing cut like a champ last summer 

[953 nut 57,904]

    I think I would start out with a new spark plug, even though it seems to be fuel related a $4.00 spark plug is a good first step. The fuel starvation could be caused by a bad fuel cap. If the vent is not working the fuel flowing out of the tank will create a vacuum that the pump can't overcome. With the tank not nearly full, loosen the fuel cap a half turn so it will get air in and try mowing with it. Let us know how you do.

[psheph43 0]

I have already put a new pulg wire coil points and condensor .. I did loose the o ring for the fuel cap and just been screwing it down do you think that could have something to do with it? ...and when I dose die its a very harsh spitting and sputtering and sometimes backfires out the exhaust and most times I have to choke it to get it started again

[953 nut 57,904]

Sounds like fuel starvation, back off on the cap and give it a try, costs nothing to try. Be sure the fuel level is low enough that it won't be splashing out. The other thought is the points adjustment, has a lot to do with timing. Try this out:

Kohler static_timing.pdf

[psheph43 0]

Thanks for the help man I'll give it a shot this weekend

[psheph43 0]

Alright triple checked the gap/ timing on the points changed fuel and tried running with cap loose .. Same result I took the deck off just to rule that out and ended up with the same result... When the engine is reved up past half way and I start to turn hard or go up a small hill the motor will back off on power and spit and sputter and pretty much lock down it sounds like its backfires out of the carb while its spitting and sputtering to a hault it runs good off a cold start for about 5 min and on a hot stat only about a minute .. I took the head off just to check the cylinder bore and make sure the valves were opening and closing all the way and they are and the cylinder looks damn good for a 30 old + machine and has a standard bore piston .. I have no clue what caused this like I said it ran great in the winter with the plow and now this ... Before I put the deck on I did change the drive belt , oil change ,and put a plug in it and since have replaced all ignition components and fuel pump ... I did have a little trouble setting up the clutch on the PTO when I mowed for the first time and may have had it to tight .. Can you overheat the PTO and possibly cause harm to the nearing behind it? Do you think the trans could be the issue ? Any help is greatly appreciated!

[Tuneup 1,433]

I read through and haven't heard a thing about the carb. You can kill it immediately when it starts to bog and then remove the fuel bowl to check for the right amount of fuel present. Maybe that will validate the pump's still OK. No guarantee that a new part actual works nowadays and you can test it at the same time with hose removed and cranking. You can completely remove it from the equation by applying a gravity feed if you have to. If plenty of fuel is in the bowl, I'd clean the carb and try again. You can always start applying more fuel when she appears to be slowing by unscrewing the main a bit more. You might also be running it fairly lean and she's  overheating on the load. Plenty of experimentation still to follow. Kudos on the ignition first approach, old timer

[psheph43 0]

Well after I did a cylinder leak down test and found air getting past both the valves I decided its time for this old girl to get a rebuild .. Have any of you used parts from isavetractors.com ? Also one other thing I noticed is the is a gap between the piston and the cylinder wall on the valve side of the piston ( the gap is brig enough to see the rings ) have any of you ran into this before? 

[Tuneup 1,433]

It's likely that the carbon buildup on the block wore the piston - typical. Mine was same - could see the top ring - but piston replacement is also typical on these machines and the bore was not worn. New piston, rings and valve lapping and she's good to go. Good luck! I'm just sitting and staring at mine with a cup of coffee in hand while the paint dries.