Static timing question K241

[pfrederi 18,128]

Working more on my neighbors 1075. K241 Spec #46323C It ran but not as well as it should.  Have the carb (Walbro) soaking and adjusted the valves (Exhaust was OK Intake a bit tight).

 

  Put on new Kohler points and decided to static time it.  In order to get the "S" centered in the sight hole (which back then was on the back of the blower housing...not convenient!!) I had to open the points to .033  that seems like a lot to me. Thoughts??? 

 

Can't run it at the moment till I get the carb cleaned and back together and the breather assembly back together ...Some PO used RTV instead of gaskets.  Have to wait on gaskets..

[Ed Kennell 39,663]

Typically a worn push rod or cam requires a smaller than design gap.  I have some that I had to use a 0.010 gap to get the timing correct.

Could the flywheel be loose, or the  push rod too long?

[pfrederi 18,128]

2 minutes ago, Ed Kennell said:

Typically a worn push rod or cam requires a smaller than design gap.  I have some that I had to use a 0.010 gap to get the timing correct.

Could the flywheel be loose, or the  push rod too long?

 

 

Flywheel doesn't look like it has moved since it left the factory.  I think I have a new push rod around here somewhere.  I will have to measure them both.

[pfrederi 18,128]

1 hour ago, Ed Kennell said:

Typically a worn push rod or cam requires a smaller than design gap.  I have some that I had to use a 0.010 gap to get the timing correct.

Could the flywheel be loose, or the  push rod too long?

 

 

After much poking around the new plunger I have i for 8hp...  more study on the parts manuals reveal that older engines used a different Kohler points 4715001  it was replaced by 4715003  BUT note the warning buried in the parts manual for engines before serial number 13007371 (= 1983) if you use the new points you have to replace the plunger.

 

Nothing is ever simple.  My existing plunger measures 1.555  (About 1-9/16")   any one know how long a plunger 4741104 is???

[Ed Kennell 39,663]

Interesting Paul.   I can't help with the plunger length, but it looks like you found the problem.  If all else fails,  shorten the plunger rod  0.010". 

[squonk 41,855]

Paul, On my 67 K301 it says the points should begin to break as the "S" is centered in the hole. Continue rotating the engine until the points reach maximum opening. Then set the gap to 0.020. I just did this and the motor runs like a watch.

[953 nut 56,651]

5 hours ago, pfrederi said:

I had to open the points to .033  that seems like a lot to me. Thoughts?

If the flywheel is in fact in the correct orientation to the cam and the motor ran well telling you all is well internally you sort of have to go with the mark To double check the mark you could bring the piston to TDC and see if the "T" mark is in the site hole. .As long as the points open at the "S" mark and it is repeatable while rotating in the correct direction it should be good. I have never had one be higher than .022 or lower than .017, but that is just my experience.

[squonk 41,855]

The engine I just did actually had the points opening AFTER TDC. It was lugging and loud. I had the head off and could see the points opening after the piston started down! I set them to the procedure I posted and man what a difference. I used an ohmmeter to catch when the points first broke with the "S" centered. Then watched the pushrod travel it's farthest point and set the gap. 

 

 

Edited June 7, 2017 by squonk

[953 nut 56,651]

15 minutes ago, squonk said:

Then set the gap to 0.020. I just did this and the motor runs like a watch.

The method I have used is not dependent on the .020" at all, The collapsing field in the coil is initiated the moment the points open, the point gap is only a starting point, not a destination. Here is the text of the method I use (after the meter is connected and initial setting of .020").

 

Now, rotate the engine SLOWLY by hand in the direction of normal rotation. When the points just begin to break, the

meter will fluctuate from zero resistance to infinite resistance. When this fluctuation occurs, stop rotating the engine,

and look in the sight hole to see where the "S" mark is. If you did it right, the "S" mark should be centered in the sight

hole at this time.

If it isn't, vary the point gap ever so slightly to either side and repeat until the "S" mark is centered in the sight hole when

the points just begin to break. When this is accomplished, tighten the adjustment screw on the points, bracing the

adjustable contact with a flat screwdriver to avoid changing the timing when tightening the screw. (Yes, I know you can't

see the timing mark in the hole on my picture...it's hard enough to shine a light and see it, let alone have it show up on a

camera. I tried.) Ironically, this engine was timed perfectly with the points gapped at 0.020", but I want to emphasize

that this is HIGHLY UNUSUAL. Most engines will not run right with the points gapped at 0.020".

[squonk 41,855]

I'm sure wear and tear on an engine will help determine what gap will be the best setting. I set it at .020. Of course the feel of the drag on the feeler gauge will also vary from person to person as well. Sure made a difference firing BTDC than after.

Edited June 7, 2017 by squonk

[pfrederi 18,128]

I painted the timing marks while i had the head off and the T mark coincided with TDC.  I used the ohm meter approach to determine the point at which the points opened.  With a .020 setting they opened after TDC.  I had to keep opening them to over.030 to get it to open at the S mark. 

 

I have ordered the 47 411 04 plunger, will be interesting to see if it is a different length than the one in the tractor.  The points on the points on the tractor were opening after TDC that is why i put on new ones. Still had to open them way up. 

 

My supposition is that at some point a PO replaced the points with the newer ones but not the plunger..  if you look the original points 47 150 01 show as NLA and replaced by 47 150 03.  There is no mention there about the need to replace the plunger on older engines (pre 1983).  (Only the little note I found in the K241 parts manual.)

 

When the new plunger arrives I will measure the two and report back...

 

I wonder if the same issue impacts 12-16 hp singles???l

 

[Dakota8338 115]

8 hours ago, pfrederi said:

I painted the timing marks while i had the head off and the T mark coincided with TDC.  I used the ohm meter approach to determine the point at which the points opened.  With a .020 setting they opened after TDC.  I had to keep opening them to over.030 to get it to open at the S mark. 

 

I have ordered the 47 411 04 plunger, will be interesting to see if it is a different length than the one in the tractor.  The points on the points on the tractor were opening after TDC that is why i put on new ones. Still had to open them way up. 

 

My supposition is that at some point a PO replaced the points with the newer ones but not the plunger..  if you look the original points 47 150 01 show as NLA and replaced by 47 150 03.  There is no mention there about the need to replace the plunger on older engines (pre 1983).  (Only the little note I found in the K241 parts manual.)

 

When the new plunger arrives I will measure the two and report back...

 

I wonder if the same issue impacts 12-16 hp singles???l

 

I have a 1978 C-141 with a 14 HP Kohler engine K321AS, Serial # 908914, Spec # 60322d, which I purchased new in '78, and have never experienced this problem.

Edited June 8, 2017 by Dakota8338

[squonk 41,855]

On June 8, 2017 at 8:30 AM, pfrederi said:

I painted the timing marks while i had the head off and the T mark coincided with TDC.  I used the ohm meter approach to determine the point at which the points opened.  With a .020 setting they opened after TDC.  I had to keep opening them to over.030 to get it to open at the S mark. 

 

I have ordered the 47 411 04 plunger, will be interesting to see if it is a different length than the one in the tractor.  The points on the points on the tractor were opening after TDC that is why i put on new ones. Still had to open them way up. 

 

My supposition is that at some point a PO replaced the points with the newer ones but not the plunger..  if you look the original points 47 150 01 show as NLA and replaced by 47 150 03.  There is no mention there about the need to replace the plunger on older engines (pre 1983).  (Only the little note I found in the K241 parts manual.)

 

When the new plunger arrives I will measure the two and report back...

 

I wonder if the same issue impacts 12-16 hp singles???l

 

Interesting. My points were opening after TDC. I loosened the points and started over and got them to open at the "S" mark. I set them from there to .020 and the engine ran fine. Then I decided to buy new points and redid every thing. Engine still runs great. The old points opening after TDC were gapped at about .015 before I moved them.

[953 nut 56,651]

1 hour ago, squonk said:

I loosened the points and started over and got them to open at the "S" mark. I set them from there to .020 and the engine ran fine.

Mike, resetting the gap on your points after static timing seems counterproductive. If you redo the timing setup you will find that moving the points undid the static timing. Once they open at the "S" that is it! tighten them then recheck.

 

[squonk 41,855]

8 hours ago, 953 nut said:

Mike, resetting the gap on your points after static timing seems counterproductive. If you redo the timing setup you will find that moving the points undid the static timing. Once they open at the "S" that is it! tighten them then recheck.

 

I just followed the instructions I posted above. After setting them I rotated the engine until the "S" was centered and the points broke. continued rotating until maximum opening and checked the gap and it was .020" rotated and checked 3 times and it stayed the same. 

[buckrancher 2,694]

the .020 point gap is just a reference static timing is the correct method also point push rod length does not mean anything ( does not matter if the push rod is worn .050 it will only push what the camshaft lobe height is ground at)

Normally what happens is the camshaft wears and this shortens the stoke for the point rod so you end up with a smaller point gap like .018 .

sounds to me that the engine has been apart before or assembled at the factory with the timing marks off one tooth or ether the crankshaft or camshaft were incorrectly orientated when they were machined originally

With that being said how you are getting a larger point gap is because you are starting farther down on the shallow side of the camshaft points lobe when you static time if the timing marks are off . this increases the length of stroke for the points push rod.  increasing the point gap

 

Brian

 

 

Edited June 10, 2017 by buckrancher

[953 nut 56,651]

1 hour ago, squonk said:

rotated and checked 3 times and it stayed the same.

    I misunderstood what you posted previously. It sounded to me like you were resetting the point gap.  

[pfrederi 18,128]

The new plunger showed up this morning 4141104.  (that is the one the parts manual says has to be put in pre-1983 engines if you use the currently available Kohler points set.

 

The new one measures 1.549 the plunger in the machine (I am guessing original) 1.553.   Will be awhile before I have time to put it back together to test the timing but this may (I hope) resolve the weird timing issue.

[Searcher60 209]

The best way to time one of these is to move the timing mark over your the PTO side, and then use a timing light. You will be there awhile any other eay.