K241S massive air/exhaust leak

[masafiddle1 7]

Hello all,

 

I have inherited a 74 B100 with 10hp K241S 46636d when my father passed away. I remembered this tractor new, so when asked, I wanted it.  It runs and mows, however, the engine slows and speeds up randomly.

I left it running and lifted the hood. 1st thing I noticed was a loose plug wire, fiddled with it and she spurred up to max rpm. But that only worked randomly as well.(will replace wire soon). 2nd and possibly most importantly I noticed a MASSIVE amount of air/exhaust coming out of the "FIN" area (see pic) Forgive me but, is this normal? I mean it feels like a high powered fan. Any other thoughts on Idle speed random variations would be much appreciated.

Edited April 11, 2015 by masafiddle1

[masafiddle1 7]

I am suspecting that this airflow is normal as it is probably blowing over from the other side. I checked the exhaust bolts and they all seem tight with a good gasket in between. Sorry for small engine ignorance, and thanks in advance to all.

[wallfish 17,142]

All that air is normal. Created by the blower fins on the flywheel from the other side. It's how the engine is cooled.

Surging RPMs (hunting) is usually caused by a dirty carb.

[masafiddle1 7]

Thanks WallFish for the tips and the welcome. I will proceed to R&I the carb, tear it down and clean it all up. Should be exciting. I plan to gradually teardown and clean and refurbish as much as possible. The cosmetic stuff I can do easily...cleaning,painting,dents and whatnot. But, I go into engine diag and work cautiously.

[rmaynard 15,774]

Also, download the Kohler service manual and check your governor settings. An improperly adjusted governor will cause surging.

[KC9KAS 4,741]

[953 nut 56,475]

  The loose plug wire may have fouled the spark plug, a few bucks for a new one couldn't hurt. Also, if the shaft on your throttle is too loose that could be a cause of hunting.

[meadowfield 2,619]

worn linkages also cause hunting...

[masafiddle1 7]

Sorry that it has taken so long to get back here. I found the "Hunting" problem. The coil to plug wire was worn and brittle and the coil ground wire was just hanging by a thread. After some acrobatics while driving with the hood up I just happened to catch a glimpse of the spark arc right as it surged. I replaced the coil wire and put a new end on the ground and "VahVoom", she's a roarin!
Thanks all.

[oldredrider 2,553]

Thanks for following up on your problem. That will help others!  Glad you got it fixed.