puzzler Kohler k301 just stops

[Mek-a-nik]

Possibly a low float or an obstruction of some kind in the needle and seat or thereabouts. Both conditions allowing it to run until it gets ahead of the fuel supply.

Have you ruled this out? Your first post indicates that you didn't check fuel flow all the way to the carb.

[38racing]

Any meaning to the muffler flame on shutdown. I know I have had it sometimes on engines when normal fuel tank runs dry.

when you shut the engine down there's no spark, so you have unburned fuel shooting into the exhaust and burning off on hot exhaust. See that often on your cheap basic "short run" mufflers on those older engines.

Like I mentioned earlier, there's a few things that can do that including valves hanging, breaker pushrod hanging, points or spark failure (condenser and/or coil, too) so I would check the ignition carefully (its easiest to access anyway) and give it a good tune up if you spot signs of burning contacts, and check the pushrod (with a magnet) to see if it is aluminum or steel.. then consider checking valves and head gasket area.

When it stops there is spark pretty much until it stops and definitely no change in spark when it starts the short surge just before shutdown. When I got home this afternoon I cut my front lawn , at least half hour without a blip. So that's 2 long runs. I will cut another section in the next day or so.

[bgsengine]

When it stops there is spark pretty much until it stops.

OK - that flame out when it "just dies" just may be your exhaust valve hanging, if it does not flame out when you shut down, but only when it dies.. But as you seem to maybe have resolved it, I'd have to bet you had carbon build up on the valve stems and the seafoam does help break that down and clean things up a bit. when those engines get worn valve guides, they do get rather a bit of carbon build up on the stems that sort of "wedges" the valve in the guide after a while and the valve does not completely close. - a hanging exhaust valve will allow air to be sucked back in through exhaust and cause a lean burn problem, hard starting (if it leaks cold) among other things, so all things considered, it may very well be a valve problem.

[38racing]

Possibly a low float or an obstruction of some kind in the needle and seat or thereabouts. Both conditions allowing it to run until it gets ahead of the fuel supply.

Have you ruled this out? Your first post indicates that you didn't check fuel flow all the way to the carb.

Boy. Time flies. I have it back at my place with exact same problem. I thought it was 2 years ago. Wow, it's been 5. I should have immediately re-read this thread. This time I thought it was bad gas. I replaced his gas with some of mine (which turned out to have water in it). So completely drained tank and refilled with good. Cold start runs about 3 minutes before shutdown. Restarts within 30 seconds and runs for less time. This time I checked valve clearance. Right on spec. I tried a separate tank. Same problem. So now I decided to run on part throttle. Ran for about 6 minutes. I increased throttle to full and it shutdown within a minute. So I think it's a float issue. Tapping side of carb made no difference. Maybe last time enough seafoam fixed a sticky float. ( he's been adding seafoam,not sure how often or how much). Is there a bowl vent that could fuel into carb? I'm thinking of putting carb through the USC. Or I found a aftermarket carb for 25 $cdn.

[bgsengine]

Possibly a low float or an obstruction of some kind in the needle and seat or thereabouts. Both conditions allowing it to run until it gets ahead of the fuel supply.

Have you ruled this out? Your first post indicates that you didn't check fuel flow all the way to the carb.

Boy. Time flies. I have it back at my place with exact same problem. I thought it was 2 years ago. Wow, it's been 5. I should have immediately re-read this thread. This time I thought it was bad gas. I replaced his gas with some of mine (which turned out to have water in it). So completely drained tank and refilled with good. Cold start runs about 3 minutes before shutdown. Restarts within 30 seconds and runs for less time. This time I checked valve clearance. Right on spec. I tried a separate tank. Same problem. So now I decided to run on part throttle. Ran for about 6 minutes. I increased throttle to full and it shutdown within a minute. So I think it's a float issue. Tapping side of carb made no difference. Maybe last time enough seafoam fixed a sticky float. ( he's been adding seafoam,not sure how often or how much). Is there a bowl vent that could fuel into carb? I'm thinking of putting carb through the USC. Or I found a aftermarket carb for 25 $cdn.

I forget - do it have a fuel pump? mechanical fuel pump, have had some where the check valves in the pump will pop loose and it can't pump enough volume.. if no fuel pump on the unit, then possibly restriction in fuel line? (check fuel flow rate?)

[38racing]

No fuel pump and I held a separate tank attached to carb with no shutoff or filter involved. But you know when I had carb off I removed needle but didn't actually blow out the inlet. That will get done when I pull the carb.

[bluemower]

Just reviewed the original post and most of the replies may apply. I would like to share my experience with an early cub equipped with a kohler 341. This occurred about 25 years ago.

the owner stated he had taken the cub to several repair shops and a similar problem was not resolved. The engine would start, but within a few seconds the engine would misfire and soon quit. As I examined the engine, something did not look right, so I compared the engine with a Kohler on my Troybilt. Apparently, the owner had somehow ripped off the external condenser while mowiing. Without any other adjustments or repairs, a new condenser solved the misfire problem. Others may explain better, however, the condenser absorbs voltage as ignition points open. This prevents arching across the points. With arching, interference with flux build up and induction will occur. A technician may not see this using only a gap spark tester.

[38racing]

Just reviewed the original post and most of the replies may apply. I would like to share my experience with an early cub equipped with a kohler 341. This occurred about 25 years ago.

the owner stated he had taken the cub to several repair shops and a similar problem was not resolved. The engine would start, but within a few seconds the engine would misfire and soon quit. As I examined the engine, something did not look right, so I compared the engine with a Kohler on my Troybilt. Apparently, the owner had somehow ripped off the external condenser while mowiing. Without any other adjustments or repairs, a new condenser solved the misfire problem. Others may explain better, however, the condenser absorbs voltage as ignition points open. This prevents arching across the points. With arching, interference with flux build up and induction will occur. A technician may not see this using only a gap spark tester.

Condenser is in tact. There's a spark on the inline tester right until she stops. Mind you the plug could be shorting. Should have new plug tomorrow.

[38racing]

Geez. i thought i had it. When I was taking the carb apart to usc it I felt that float wasn't dropping enough. I found a tang on it that hits against the brass inlet seat. I bent it a bit and float now drops further. Put it all back together and she ran almost long enough that I thought it was fixed. But alas, no. Restarts within 30 seconds. Figuring gas shortage I sprayed carb cleaner into air intake at the first hint of rpm drop. It didn't recover. That puzzles me if its fuel starvation. My only other observation is what sounds like a gurgle from the carb. Today I also tried it on reduced throttle while I did another task. When I came back it had still stopped. Can't say exactly how long it ran. I could go into carb again and ensure that sides of inlet needle are nice and smooth but maybe I'll make my next step the replacement carb.

[bgsengine]

Geez. i thought i had it. When I was taking the carb apart to usc it I felt that float wasn't dropping enough. I found a tang on it that hits against the brass inlet seat. I bent it a bit and float now drops further. Put it all back together and she ran almost long enough that I thought it was fixed. But alas, no. Restarts within 30 seconds. Figuring gas shortage I sprayed carb cleaner into air intake at the first hint of rpm drop. It didn't recover. That puzzles me if its fuel starvation. My only other observation is what sounds like a gurgle from the carb. Today I also tried it on reduced throttle while I did another task. When I came back it had still stopped. Can't say exactly how long it ran. I could go into carb again and ensure that sides of inlet needle are nice and smooth but maybe I'll make my next step the replacement carb.

when carb is off, and still a bit of fuel in bowl, turn it upside down and see if it drains gas through any holes (The bowl vent, if plugged, can cause vapor lock) if you have gas run out of any non-jet holes, your vent is probably OK.. just have to make sure when assembled, that vent is not plugged off by air horn gasket..

However, if adding a shot of carb cleaner won't keep it running, probably is not a fuel problem.. but could be a valve issue (valve hanging?)