K341 Troubles, Random "sputtering" - Calling engine Pros

[bmsgaffer 2,071]

Hi all!

 

I am in desperate need of help on this engine. Long story short: I had this engine rebuilt maybe 15 years ago. It sat on the shelf until I had time to put it in this tractor about 8 years ago. It has had this problem, or a version of it since I had installed it. The original machine shop has closed up and another local shop charged me $400 and told me "they all do that". I have only run it about 35 hours due to this problem that I can't solve. 

 

I know that I have replaced the carb 3 times (2 China, 1 nice used Kohler), coils, wires, plugs, condenser, and points have all been done (originally it had a transdenser on it but that is now a normal condenser). The head gasket has been replaced at least twice. The valves were cleaned and lapped and the most recent guy says they seem perfectly free.

 

The problem SEEMS to lessen when I first adjust the valves, but then it gets worse as it runs. It is NOT consistent. Most of the time, it gets better when put under a heavier load, but not consistently. 

 

I can't find anyone around here that knows their stuff enough to help me out. I am sure they are out there, just can't find them.  I would be SO grateful if anyone could point me in a direction or to someone who can help. 

 

Original Video:

 

 

Worst It had been a year later:

 

 

Most recent (first hiccup is about 30 secs in):

 

[953 nut 66,822]

16 minutes ago, bmsgaffer said:

(originally it had a transdenser on it but that is now a normal condenser)

Is that what is arcing and sparking in front of the engine?

22 minutes ago, bmsgaffer said:

 

The problem SEEMS to lessen when I first adjust the valves, but then it gets worse as it runs.

Have you checked the valve lash with the engine hot?

 

[kpinnc 18,601]

One other often overlooked item: check your points gap and timing. Of course an "iffy" condenser can make an otherwise good engine not run so good. 

 

That being said, on any of my Kohler machines I dump the carb bowl every couple months. You might be surprised how often they get alot of goop in them. 

[ineedanother 2,501]

What fuel are you running? You might want to try 89 or 90 octane.

[pfrederi 20,741]

In the last video engine ran ok until about 2:20 then it seemed to want to die but at about 3:00 recovered and ran ok.  (Did I get that right I assume you didn't change the throttle)

If it were a heat related Electrical issue (coil) it wouldn't recover (usually)  .also if it was a valve problem that was heat related it wouldn't recover until it cooled down.

(have you hooked up a spark tester to see if it changes color as it stumbles.  I do not think so but you never know.  If it is ok then

 

That sort of leaves fuel.. Crap in the carb or blockage in the fuel tank screen???

[ebinmaine 79,266]

2 minutes ago, pfrederi said:

blockage in the fuel tank screen

 

Gas tank vent?

[bmsgaffer 2,071]

3 hours ago, 953 nut said:

Is that what is arcing and sparking in front of the engine?

Have you checked the valve lash with the engine hot?

 

 

Yes, its a blue LED flashing. Its like a points-saver. 

I have struggled hot since the muffler crosses the front of the engine on this one and everything gets really hot. That is a solid idea though and may try to figure out how to do that. 

 

1 hour ago, kpinnc said:

One other often overlooked item: check your points gap and timing. Of course an "iffy" condenser can make an otherwise good engine not run so good. 

 

That being said, on any of my Kohler machines I dump the carb bowl every couple months. You might be surprised how often they get alot of goop in them. 

 

I have tried the stationary gap timing and adjusting while running, but I am no pro on hearing what is "right" (i can tell when it gets bad though). The last guy I sent it to readjusted it also and says its fine. I will replace the condenser again as the sporadic nature makes me think electrical. 

 

1 hour ago, ineedanother said:

What fuel are you running? You might want to try 89 or 90 octane.

 

I usually grab mid-grade (89 I think?) and throw some sta-bil in. 

 

1 hour ago, pfrederi said:

In the last video engine ran ok until about 2:20 then it seemed to want to die but at about 3:00 recovered and ran ok.  (Did I get that right I assume you didn't change the throttle)

If it were a heat related Electrical issue (coil) it wouldn't recover (usually)  .also if it was a valve problem that was heat related it wouldn't recover until it cooled down.

(have you hooked up a spark tester to see if it changes color as it stumbles.  I do not think so but you never know.  If it is ok then

 

That sort of leaves fuel.. Crap in the carb or blockage in the fuel tank screen???

 

Sorry, I should have clarified all the large changes were throttle adjustments. I am specifically looking at the random "pops" when running at a steady RPM. 

 

I agree that I was thinking if it was heat or valve related it would be more consistent or, like you said, not recover. It starts within a minute of the engine running and just continues to happen. 

 

Thats a great idea, I dont have a spark tester, I will go pick one up.  

 

1 hour ago, ebinmaine said:

 

Gas tank vent?

 

The tank cap is broken and if anything is overly vented. 

 

 

Everyone: Thank you so much for jumping in here. I have a few things to try, maybe starting with the spark tester and condenser (and maybe coil and wire while im there just to rule it out). Keep the good ideas coming!

[Bill D 2,935]

Try running a jumper from the battery positive to the coil positive.  If the stumble goes away then you have a bad key switch or safety switch that's causing problems. 

 

 Also,  check and clean your grounds.  This is a powered ignition system so dirty electrical connections can cause problems.   

 

Just some thoughts. 

[kpinnc 18,601]

3 hours ago, bmsgaffer said:

usually grab mid-grade (89 I think?) and throw some sta-bil in. 

 

Whole other can of worms, but many of us are very much pro "ethanol free" on fuel. Personally, I put the first gallon in a vehicle to ensure no ethanol gets in the gas can. I don't care what anyone says, ethanol is not good for carburetor equipped anything. 

 

 

[ebinmaine 79,266]

Sta-bil has been well proven to slow down the degradation of the gasoline whether it is ethanol free or not.

 

However, it has also been well proven that it does absolutely nothing to negate the negative effects of ethanol.

 

Around our acreage we have no ethanol, no additives, and no problems.

[squonk 47,012]

The black hoods have an inline fuse in the harness  that powers everything. It isn't sealed to the weather. Check that for corrosion and cooties. 

[kpinnc 18,601]

3 hours ago, squonk said:

corrosion and cooties

 

I'm using that one! 

[squonk 47,012]

51 minutes ago, kpinnc said:

 

I'm using that one! 

[Handy Don 16,766]

The video didn’t show the carb/governor linkage while running. Is everything there snug?