Odd problem with Kohler K 181

[jbeasley@wisc.edu 2]

Hi -- I thought I posted before, but can't find it now, so perhaps I didn't actually submit.  I have a K 181 on a Gravely snowblower.  It starts fine, and runs well for about the first 10 minutes.  After that it bogs down under load and even when load removed it runs slowly and without much power.  Now, here's the odd part -- if I turn the switch off after a couple of seconds it comes up to full RPM and power.  When I continue to use it, I have to turn the switch off every 30 seconds of so if I'm putting it under load.  When the engine is not fully warm, turning the switch off leads, as expected, to it dying immediately.  It restarts without problem.  Any ideas will be appreciated.

John (a newbe).

[Achto 28,939]

 

I'm not familiar with Gravely models.

 

Does this model have points and condenser? If so it may have a bad condenser.

Is this a new problem or did it arise after changing a part?

[WHNJ701 4,165]

Wiring issue? something grounding out?

[pfrederi 18,395]

Kohler could be battery/points, magneto points or even breakerless ignition    Need more info

[lynnmor 7,626]

Try playing with the choke, does it make it better or worse when you move towards more choke?

[peter lena 9,114]

newbie, sounds electrical to me , like a condenser  ?   , verify what you have before  it starts , then  back track or enhance that  point. possible frayed wire or rusty ground point ?  do you have a couple of  alligator  clip jump wires ? to jump over electrical contacts ?  how about your fuel flow ?  while its running , get some aerosol carb  cleaner , air cleaner off , and alternately use your hand to block the air flow while sucking thru that cleaner , that will suck out the float bowl and get things going. notice any gains and go after that . just some of what i have done , let us know , pete

[Pullstart 64,941]

 

If there is an external coil, they have been known to become weak after getting warm.  A short break of usage might cool it enough to fire back up.  As you can see, there are many possibilities to your issue, I agree with pretty much everything above 

 

I was just talking with grandpa this morning about asking for help on forums.  Sometimes with various topics, every single person gives you their definite issue.  Many people don’t have any experience.  You just have to thumb through the b.s. to find the answer you need.  Here, it seems like every person is giving you heartfelt advise because we care to keep this old iron moving 

[stevasaurus 23,107]

Are you saying that after it is warm, you turn the kill switch off and back on and the engine does not kill, but runs better??  

[jbeasley@wisc.edu 2]

Wow, thanks to all for the replies.  It does have a magneto ignition with external coil. It does not have a separate kill switch, but yes, when I turn the ignition switch to off it perks up and then runs better for 5 or 10 seconds before it starts to die, and then when I turn the switch back to run, it does fine -- again for 1 minute or so, depending on load.  I had not put any new components in (have new condenser and plug but haven't gotten around to  putting them in. Fiddling with the choke didn't help.

 

However, since I posted, I checked the plug which was somewhat carbonized and got a new one -- and it is a slightly different style.  Perhaps the wrong plug has been installed sometime in the past.  I got to thinking that if the mixture is too rich the plug might be getting crudded up and then when I turn the ignition off it diesels a bit, somehow cleaning the plug?

In any case, with 3 to 6" of snow predicted for tomorrow I'll get lots of chance to try it out. I'll let you know.

 

For the person who commented regarding Old Iron, I also have, among others, a working 1947 Gravely and a 1947/48 Cletrac, which runs reasonably well.  Old Iron is addicting.

 

 

[pfrederi 18,395]

 

1 hour ago, jbeasley@wisc.edu said:

Wow, thanks to all for the replies.  It does have a magneto ignition with external coil. It does not have a separate kill switch, but yes, when I turn the ignition switch to off it perks up and then runs better for 5 or 10 seconds before it starts to die, and then when I turn the switch back to run, it does fine -- again for 1 minute or so, depending on load.  I had not put any new components in (have new condenser and plug but haven't gotten around to  putting them in. Fiddling with the choke didn't help.

 

However, since I posted, I checked the plug which was somewhat carbonized and got a new one -- and it is a slightly different style.  Perhaps the wrong plug has been installed sometime in the past.  I got to thinking that if the mixture is too rich the plug might be getting crudded up and then when I turn the ignition off it diesels a bit, somehow cleaning the plug?

In any case, with 3 to 6" of snow predicted for tomorrow I'll get lots of chance to try it out. I'll let you know.

 

For the person who commented regarding Old Iron, I also have, among others, a working 1947 Gravely and a 1947/48 Cletrac, which runs reasonably well.  Old Iron is addicting.

 

 

  Do you have a spec number for the engine...A mag with an external coil would be unexpected.

[montclair 1]

6 hours ago, pfrederi said:

 

  Do you have a spec number for the engine...A mag with an external coil would be unexpected.

i ha a k-321 kohler in a  70s cub cadet that would idle ok but giving it throttle it would run rough then die But would start up idle good till more throttle was applied  it would sputter then die It had a external points condenser coil had a gen/starter All it was was a weak bad condenser Changed the condenser and problem solved

[jbeasley@wisc.edu 2]

Problem solved -- I think.  It turns out that somebody (probably me!) had replaced the spark plug with the wrong type -- guess my hardware store didn't have an exact replacement for the Champion RJ8C specified in the manual.  I went to my small engine shop and they cross referenced to an NGK BR6S.  Installed that and things seemed to run fine! 

I'll have to check what type of carburetor I have next time I'm out where the machine is, Kohler or Walbro and probably lean it out more.  For the person who asked the engine is a K181 s, 30718C 11053702 

My apologies regarding my misstatement on the ignition -- it is battery with a coil.  

Again, my thanks for all the replies.

[gwest_ca-(File Mod) 11,282]

Kohler made your engine serial in 1981.

https://www.partstree.com/models/k181-30718-kohler-k-series-engine-made-for-gravely-8hp-6kw/

 

Garry