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 66,805]

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 18,581]

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 2,500]

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

[pfrederi 20,727]

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 79,254]

2 minutes ago, pfrederi said:

blockage in the fuel tank screen

 

Gas tank vent?