k161s points and timing

[mooman3121 58]

Hi folks!  I have a k161s  spec # 28626E serial # 568464. My issue is that I cannot get this engine to run right despite my best efforts- have rebuilt the carter carb after soaking for a week in berry mans and I have pretty much ruled out the carb due to the strange things going on with the ignition. First off I have to gap the points at .030 instead of the recommended .020 to get it to run. checking the static timing the points don't break until TDC timing mark on flywheel instead of the 20 degree advance mark. When running the points have a lot of bright blue sparking going on- have tried 2 different condensers but no change. If Clean up the points with some sand paper and reset them for 30 it runs pretty good for awhile until the sparking burns them up again and then it will barely make rpms. when i got the tractor it had no points condenser or coil and got all kohler parts on line for the k161. I also wonder if I have the ACR on this engine or the auto spark advance and how might that be a factor if at all. Kind of at the end of my rope here for solution so looking for any help you all may be able to give- Thanks!

[wallfish 17,247]

Was it rebuilt?

Check the flywheel key

Curious if the timing marks on the cam and crank gears are lined up. That could delay the points opening and the need to retard the timing with the larger gap if it was off

[stevasaurus 22,995]

Right...no way you should have a gap at 0.030  I'm thinking you have ACR, but that is not going to make any difference.  The ACR just holds the exhaust valve open a little to keep the compression low when cranking, or pulling the starter rope.  I'm thinking you are a tooth off with the crank and cam shaft.  Like John is saying.

[rmaynard 15,848]

Very easy to put the engine back together with the camshaft gear misaligned with the crankshaft gear. After making sure that the alignment is correct, set the points to .020. While checking the static timing, be sure that you are rotating the engine in the correct direction (clockwise while viewing the flywheel). I have made the mistake of rotating it backwards and wondering why I was having problems.

 

 

 

Edited June 14, 2020 by rmaynard

[squonk 42,056]

The sparking and burning up is due to the wide gap. I concur. Check the cam timing

[953 nut 57,034]

4 hours ago, mooman3121 said:

When running the points have a lot of bright blue sparking going on- have tried 2 different condensers but no change.

The body of the condenser has to be grounded and the lead has to be connected to the "-" side of the coil along with the wire to the points. The wire from the ignition switch will connect to the "+" side of the coil.

With a battery ignition system, the ignition points are closed the majority of the time. With the points closed and the ignition switch ON the primary windings of the ignition coil have current flowing through them and are developing a magnetic field in the iron core of the ignition coil. The moment the ignition points open the magnetic field collapses and induces a momentary high voltage pulse in the secondary windings of the coil which goes through the spark plug wire and arcs across the gap of the spark plug. If this occurs in the presence of a compressed fuel/air mixture of the proper ratio an explosion will occur within the cylinder. If this explosion occurs at the proper time in the engine’s cycle there will be pressure applied to the piston forcing it downward on the power stroke. The ignition points will continue to open further after this has occurred. How far they open is immaterial, their work has been done for that cycle of engine operation. What is important is when they open relative to the position of the piston on its compression/power revolution. If it occurs too soon there will be backfiring, too late and there will be a reduction of power. In the case of our Kohler engines the sweet spot is twenty degrees Before Top Dead Center, that is what the “SP” mark on the flywheel is set to). At the moment the points open the condenser quenches the arc across the points extending their life, the rest of the time it just sits there.

4 hours ago, mooman3121 said:

k161s  spec # 28626E

Your engine has a spark advance cam and can not be timed with static timing.

Ignition timing on Kohler engines.

 

Gapping the ignition points at .020 has always been the standard answer to how points should be set. That probably will get you into the ballpark where the engine will run, but with a bit of additional effort you can improve the engine’s power and performance.

The Kohler engine manual in the Red Square files section covers two methods for setting the ignition timing, Static Timing and using a Timing Light. This manual is a relatively new manual and it overlooks the fact that many of our engines were built prior to the ACR (automatic compression release) camshaft.

Earlier engines (mostly 1965 and earlier) had a Spark Advance camshaft that can not be timed using Static timing. At rest (and very low RPMs) the timing is retarded to fire slightly after TDC. The timing mark (SP) on your flywheel is at twenty degrees before top dead center but at rest the points on these engines break about ten degrees after top dead center. The only reliable way to check or set the timing on these engines is with a timing light.

There are a couple ways to determine what camshaft you have. Presuming the camshaft in your engine is the one it was born with the data plate on the engine has a suffix that can tell you what camshaft was used. The table below will tell you the suffix applicable to your engine. The other way to determine what camshaft you have is to remove the cam gear cover and take a look. If you see a mechanism attached to the cam gear it is the ACR cam.

 

 

The following engines have the spark advance camshaft;

K-141, Suffix prior to “C”

K-161, Suffix prior to “J”

K-181, Suffix prior to “D”

K-241, Suffix prior to “D”

[mooman3121 58]

Ok thanks all for the info! I will check the camshaft timing as who knows what has been done to this engine after all these years....

[mooman3121 58]

 UPDATE- ok we got the motor out and base off- The timing marks that i highlighted appear to be correct, the crank tooth lines up with the cam mark when rotated- the timing marks on the stem of the advance cam are correct as well- springs on the weights are good and no evidence of excessive wear. Am using the correct marks as those were all I could find.....

[mooman3121 58]

Kind of confused by that raised pointer on crank being almost between teeth.

[953 nut 57,034]

Here are a couple of pictures from an excellent thread @prondzy did on engine rebuilding.     

Is your points cam properly aligned?

Edited June 17, 2020 by 953 nut