Kohler CH18 enging running rough
 

My 1864 has been acting up lately...lacking power. I checked both spark plugs (just put in new autolite plugs) two weeks ago, changed oil to get ready for leaf season etc.

Today, I tried starting the engine with the right plug wire pulled. It seemed to run ok, but not normal at low idle. Then, I pulled the left plug wire, (reconnecting the right) and tried to start it again. No such luck. No start.

I'm guessing that the ignition coil for the right cylinder is the problem. Is it possible that the coil is open. The engine seemed to be running hotter than usual the last time I mowed. Could that have caused the problem?

Any recommendations on where to order coils from? (if that is the problem)

Help is appreciated!

first check for spark , second check for compression, and report back with what you find

CH18
 

Checked for spark...good. Checked for stuck valve...good. Compression test...good. Checked conductivity of spark plugs...NOT GOOD!

I installed 2 Autolite plugs a few weeks ago. They worked the next time I cut the lawn. Did not work the last time. I have had trouble in the past with non-conductive Autolite brand (from Walmart) plugs..seems I haven't learned my lesson about using cheap plugs.

The apparent problem is that the top of the plug is "non-conductive" where the boot wire attaches. Tested with a continuity tester to determine this. Removed coating with a wire wheel and reconnected. Started right up, smooth idle and plenty of power at high RPM.

So I got things workin' but I want to find a better quality set of plugs that will do the job. I believe the originals were Champion RC12YC which may not be the best for the engine. Does anyone have a solid performer that will make the engine run well? Anything from NGK or other brands?

Your thoughts are very much appreciated!! :biggrin2:

I use Champion 2071 but they are no longer available , i bought a few and they will see me out
Great plugs
Go to a cross-reference site for plugs
Check online you may still find some 2071
heres one a bit dear
https://www.ebay.com.au/itm/15595772...Bk9SR7j4kezaZA
Oz

i've had good results with champion plugs

CH18
 

Thanks for the replies...Going to try some NGK BCPR5ES (6130) plugs that cross reference with Champion RC12YC. My Autolite plugs are working since I cleaned off the tops where the boots connect, however I'm going to change them out for the NGK's to see if I get better results...:biggrin2:

Kohler CH18 engine running rough
 

Well...I finished doing my leaves yesterday...something still seems amiss (no pun intended) with my engine in the 1864. Considering that it is around 28 years old with about 1300 hours, I'm pretty certain that a bad ignition coil is the problem. I seems that one spark plug is not firing consistently, causing a loss of power. The engine actually stalls out at low idle. :bigthink:

So I bit the bullet and ordered a new pair of Kohler ignition coils, which I should have in a few days. Hoping to pull the engine with my loader before I have to switch to the plow on my winter rig. For the record, I HATE SNOW!!!

Will keep you posted...