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953 nut

Static Timing a Kohler with Starter/Generator

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rdeanrj58

Very interesting 953nut .                    I remember setting the timing this way on a Tecumseh a long time ago.  The only difference was I used a dial indicator that screwed into the spark plug hole.  A specification was given for how many thousandths of an inch before tdc the points should open. Is there a spec like this for Kohler?

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ebinmaine

Thanks for sharing that Richard!!

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953 nut
41 minutes ago, rdeanrj58 said:

Very interesting 953nut .                    I remember setting the timing this way on a Tecumseh a long time ago.  The only difference was I used a dial indicator that screwed into the spark plug hole.  A specification was given for how many thousandths of an inch before tdc the points should open. Is there a spec like this for Kohler?

The spark plugon a Kohler is not located over the piston, so, no there isn't.

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oliver2-44

Excellent write up @953 nut

I did this to the tired K341 in my C-160 and it helped extend it life for a while.

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squonk
Posted (edited)

I had k301 that also had the points opening after TDC. It started ok but it would labor under load and was too loud no matter what muffler was used. Did the same procedure but used a meter with a beep function. Didn't have to watch the meter. Kept my eye on the hole and listened for the beep to stop.

Edited by squonk
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The Gman

Great instruction 953. I did a video series a little over a year ago when I rebuilt a KT17 II...... for the second time due to a govenor problem. Here is the clip from setting the timing

 

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953 nut

@The Gman,  good video!   As there are very few threads on here about the K Twin engines and you apparently are our resident expert on them, would you be so kind as to start a thread on your rebuild?  It would be very helpful to others.       :text-thankyoublue:

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Herder
On ‎3‎/‎12‎/‎2019 at 6:24 PM, 953 nut said:

 The Benefits of Static Timing on Kohler Engines

Last year I purchased a nice 953 that started and ran OK, but was lacking something performance wise. Throttle response was sluggish and performance was lackluster. I renovated the fuel system. Replaced the fuel line and added a filter, rebuilt the fuel pump and carburetor (float was a little low but otherwise fine). The outcome was a marginal improvement.

I moved on to the ignition system, points looked good and were gapped at .020”. Replaced the spark plug and disconnected the condenser, no noticeable improvement. I then replaced the points with a new set of Kohler points and began the process of setting the timing utilizing the Static Timing Method.

This K-241 is equipped with a Starter/Generator and the process is not as easy as the newer models. The sight hole is through the bearing plate just below the bracket for the S/G itself. The marks you are looking for are stamped on the back edge of the flywheel and after fifty-five years they were indistinguishable due to rust.

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After sanding off the rust you can see the stamping. (while the tins are off the engine you can clean the cooling fins, they needed it!)

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I painted the marked area with a light coat of Almond spray paint and used ink markers to make the markings easier to read, I also extended marks over the edge so they could be seen from the outside with the flywheel on.

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The new points were gapped at .020” and the timing was checked, turns out the points were opening at about six degrees after TDC rather than twenty degrees before TDC. I proceeded to adjust the points to set the timing to the desired twenty degrees before TDC and wound up with a gap of .036”. The result of this was a K-241 that starts instantly and has good crisp throttle response.

 

 

For those who are interested in more details of the why and how of static timing; read on!

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.

The PDF we refer to on this site for static timing of the later model engines calls for an Ohm Meter to be used (PDF attached below). I prefer a 12 Volt Test Light. The light will be connected between the battery “+” terminal and the lead that connects the points to the coil (disconnected from the coil). When the points are closed the light will be on, the moment the points open the light will go off. You don’t have to be focused on if like you would on a meter. With the test light situated near the sight hole for the flywheel (spark plug out so the engine will turn with ease), turn the flywheel slowly by hand in the clockwise direction (counter-clockwise if on the PTO end) until the moment the light goes out. If the “SP” mark is centered in the hole you are done, if not you have a little work to do. This was the point where extending the lines to the outside came in handy. If the points are opening too late, they need to be opened further, if it occurs too early they need to be closed up some. Make gradual adjustments until the “SP” mark on the flywheel is centered in the sight hole at the moment the light goes out. Now tighten the screw securely and turn the engine over several revolutions to be sure the points are consistently opening at the proper moment.

Kohler static_timing (1).pdf

Thank you 953nut, I am going to print this out and keep as a quick reference.  But most importantly we need to see some pics of the 953 you purchased last.:D

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richmondred01

I still use a timing light.

However, A third hand would be nice

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953 nut
On 3/15/2019 at 8:02 AM, Herder said:

But most importantly we need to see some pics of the 953 you purchased last.

:hide:          I'm doing a little modification (top secret, don't tell anyone) but I will post when finished.           :D

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Herder
53 minutes ago, 953 nut said:

:hide:          I'm doing a little modification (top secret, don't tell anyone) but I will post when finished.           :D

:ph34r: looking forward to seeing some pic's.

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ebinmaine
Just now, Herder said:

:ph34r: looking forward to seeing some pic's.

:text-yeahthat:

 

Richard's holdin' out on us.

I'll try to let it slide..... For awhile....

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