K301 troubleshooting

[tinnerjohn]

Twice in a row, after mowing for 10 minutes or so it backfires through the exhaust and shuts off. Last time it did that, then backfired through the carb, today I didn't try starting it back up. But after the last time (a week or so ago ) I had left it sitting and my wife started it and moved it with no problem. Started fine this afternoon before I started mowing. The coil seems cooler than the engine. I'm wondering where to start checking before I fire the parts cannon at it! Thanks

 

[T-Mo]

Did it start immediately after each time it died? Start with the usual suspects, spark, fuel, air, etc. Run it without the cap on the gas tank to see it that eliminates the problem.

 

[tinnerjohn]

Tries to start but it backfires through muffler, started and ran fine cold. Tried the gas cap, seems its OK. Unfortunately (or fortunately) its been years since I've had to work on any engine, so the memory is a little dusty on some of this. It's one of those times when you think you should know the answer but can't remember.

 

[Bill Hudson]

"... before I fire the parts cannon at it!" John, now that was good for a hearty laugh.

 

[Peter Person]

Couple of possibilities.
Running too rich. What do the plugs look like?
Carbon buildup on the valves, not allowing them to seat properly.

 

[tinnerjohn]

Couple of possibilities.
Running too rich. What do the plugs look like?
Carbon buildup on the valves, not allowing them to seat properly.

Now that I think about it my Grandson may have played with the carb adjustment, I'm going to find the manual and check that and the plug. The really aggravating thing is it's run good since I got it several years ago, all I've had to do is routine maintenance.

 

[red agony]

Now that I think about it my Grandson may have played with the carb adjustment, I'm going to find the manual and check that and the plug. The really aggravating thing is it's run good since I got it several years ago, all I've had to do is routine maintenance.

Tries to start but it backfires through muffler, started and ran fine cold. Tried the gas cap, seems its OK. Unfortunately (or fortunately) it’s been years since I've had to work on any engine, so the memory is a little dusty on some of this. It's one of those times when you think you should know the answer but can't remember.

I had a K301 for years and then it gradually started to backfire when shutting it down. I adjusted the valves and it lasted for a couple years. Then the valves were out of adjustment again. After disassembly I found that the exhaust valve stem was worn thin. I ended up replacing the valves. It’s been good for a couple years now. I wonder if it was just it’s time 30 something years old, or ? I have been more careful about what oil I’m using, but time will tell if that’s the reason.

 

[JohnMihevic]

Another possibility could be the coil, that start to fail when it gets hot. When it is in "failure mode" check to see if you have a good spark -- or just replace the coil.

 

[tinnerjohn]

Another possibility could be the coil, that start to fail when it gets hot. When it is in "failure mode" check to see if you have a good spark -- or just replace the coil.

The coil is a possibility I thought about too. Unfortunately I've had a string of bigger problems so haven't had a chance to work on it. It could be getting tired, I know it was rebuilt sometime before I got it, its a 65 or 66, should still be under warranty, that was only a couple years ago wasn't it?

 

[JohnMihevic]

The coil is a possibility I thought about too. Unfortunately I've had a string of bigger problems so haven't had a chance to work on it. It could be getting tired, I know it was rebuilt sometime before I got it, its a 65 or 66, should still be under warranty, that was only a couple years ago wasn't it?

I had stomach surgery 30 years ago. A couple of years ago, I felt a "pinching" at the bottom of the scar where the stiches ended. I went in to the same Dr. He said it was where they left too much of a loose end of the stich. He went in and cut it off. No problem now. I asked him if I could get this fix under "warranty repair". He said the original surgery was only covered for 1 year under warranty. I got a good laugh out of him.
Good luck with your problem.

 

[tinnerjohn]

I had stomach surgery 30 years ago. A couple of years ago, I felt a "pinching" at the bottom of the scar where the stiches ended. I went in to the same Dr. He said it was where they left too much of a loose end of the stich. He went in and cut it off. No problem now. I asked him if I could get this fix under "warranty repair". He said the original surgery was only covered for 1 year under warranty. I got a good laugh out of him.
Good luck with your problem.

That's better than mine. My left knee was replaced last Nov. 30. Sometime in early June I knelt down to adjust the cultivators with no problem. but when I stood up the knee hurt. I waited a couple days, then decided since it still hurt I better get it looked at. The first opening was about 4 weeks out, OK I can live with it. Went to the appointment, the Docs first words when he walked in with the X-ray were "You know your out of warranty", then "what the H--- did you do?). I had broken the knee cap, fortunately the plastic wear plate they put in is holding together while it heals, just aggravating as it still hurts some and I can't get down again for awhile.