K181 Kohler Shuts Down Under Load

[Joebag 17]

Hi every one my 876 wheelhorse with the k181s 8hp engine. She will start up at just the slightest bump of the key, andwill idle and rev noprob. But she will shut down once it is under a load. She throws out a pretty good lot of bluesmoke at times when you first start her, and  even some while starting to get under load. So  I thought it may have been the carb. I cleaned it and put back together, but still does the same thing. What do you all think it is? I then thought that maybe that the piston and rings may be worn so I took the head off and checked for slop on top of the piston, no movement an walls are as smooth as silk. I then thought well maybe the govenor may need to be adjusted so I tried to set it. But the little shaft that the gov link is rideing on you know the one that you have to loosen the bolt in order to move the gov. backwards making sure the carb. is wide open. Well anyway it does not stop or tighten it only spins and spins  or turns and turns which everway you want to look at it. So my last thought is the fuel pump. What do you all think I now have the engine setting here off the frame waiting on parts to arrive for a rebuild.

Here is what everything looked like

 

then after cleaning best I could

 

 

Here is the Gov

 

 

 

Here is the carb

 

 

Here is were it is ATM waiting on parts

Edited January 29, 2017 by Joebag

[Digger 66 3,481]

Fuel pump ?

Partially clogged filter ?

 

Not sure if these are present on your model but I'd start looking at fuel delivery if you have all the other bases covered .

 

The experts will be along shortly .....

 

 

 

 

 

 

 

Edited January 28, 2017 by Digger 66

[pfrederi 17,741]

Which is the little shaft you mention  is it the cross shaft that spins and spins??????

[Joebag 17]

yes the cross shaft is the one tht spins an spins

Edited January 28, 2017 by Joebag

[artfull dodger 394]

Will it restart right after it shuts down?   Kohlers are known to stick thier exhauts valves open when nearing rebuild time from coked up oil and carbon on the valve stem.  This will only happen when the engine is hot and the metal expands and the valve sticks.   I have also seen points and condensor that are fine at idle but will break down under a load and cause a shut down.  Once again, heat, hot/cold cycling are to blame.  When I get one like this, I have my compression tester, plug wrench on hand, and my spark testing light already on the plug.  Run it till she stalls, as she stalls, is there still spark(ie the light stil flashing as the engine shuts down), if not you have a ignition issue.  If spark remains as she shuts down, then as soon as the engine stops, remove the plug, install the compression gauge and crank the engine over ASAP.  Sometimes with  good LED penlight you can look down the plug hole and see the exhaust valve(this is the one that sticks). And that Gov shaft should not just spin, it should turn to a pont and stop, that is how you set the Gov to control rpms.  You want 3600 under load + or - 50rpm   Load needs to be like a mower deck or snow blower let me know what you find.  It will over tach a bit no load, but if your mowing, you want ful rpm to get the most out of the mower deck.  If you do not mow/snowblow anymore, set it at the 3600 no load.      Mike

Edited January 28, 2017 by artfull dodger

[Joebag 17]

Thnx artfull dodger I am unable to run it now because I have the engine off. But yes it will always start right back once it shut off, and yes the light would continue to stay on. What I mean but under load is like going up a hill, or pulling a plow, but as for setting it to specific RPM I don't know what that would be other than idle and wide open because I don't have any tools or tachometer sure of any sort to test. So at least we know that the governor is one of the problems all their way to buy the entire on Chelada. shaft, governor, seals, everything that I needing

[Elkskin's mower junkyard 1,117]

one thing that comes to my mind. pull head check valves. i bet ones not seating. another thing is hows the airfilter?

[stevasaurus 22,764]

Joe, you have a couple things going on.  Can you put a picture of the top of your piston, now that you have the head off.  If it kind of looks like this...that clean area from 12 to 4 o'clock shows oil blow by, and you need to rebuild the engine first.  That is the blue smoke...does not matter if it start up or under load.

The other thing you have going on, is the governor.  Your engine is never going to run under load if that cross shaft is not locked with that lock nut.  If it still turns when that net is tight, it is not doing what it is supposed to do.  Rebuild the engine first (I just tore down my K181 on my 876...taking it to the machine shop Monday).  When you get it back, let's put it back together.  Check out Mike Prondzy's thread in the "Reference" Section/Engines...K181 rebuild.  The manual, if you do not have it, is in the manual section under engines.  Check out the manual and read it...everything you want to know...and we are here to walk you through it. 

   I hope you know that you can not just change the rings and put it back together, you need good measurements and either bored and/or cross hatching.  Checking the valves, tolerances, etc.  It is not a huge project, but you are just wasting your money if you do not do it right.

   I used a ratchet strap to hold the fly wheel to get the castle nut loose, and then to use the puller to get the fly wheel off.  I did not take the engine off the horse until I got all the pulling stuff off the engine. 

[Joebag 17]

1 hour ago, stevasaurus said:

Joe, you have a couple things going on.  Can you put a picture of the top of your piston, now that you have the head off.  If it kind of looks like this...that clean area from 12 to 4 o'clock shows oil blow by, and you need to rebuild the engine first.  That is the blue smoke...does not matter if it start up or under load.

The other thing you have going on, is the governor.  Your engine is never going to run under load if that cross shaft is not locked with that lock nut.  If it still turns when that net is tight, it is not doing what it is supposed to do.  Rebuild the engine first (I just tore down my K181 on my 876...taking it to the machine shop Monday).  When you get it back, let's put it back together.  Check out Mike Prondzy's thread in the "Reference" Section/Engines...K181 rebuild.  The manual, if you do not have it, is in the manual section under engines.  Check out the manual and read it...everything you want to know...and we are here to walk you through it. 

   I hope you know that you can not just change the rings and put it back together, you need good measurements and either bored and/or cross hatching.  Checking the valves, tolerances, etc.  It is not a huge project, but you are just wasting your money if you do not do it right.

   I used a ratchet strap to hold the fly wheel to get the castle nut loose, and then to use the puller to get the fly wheel off.  I did not take the engine off the horse until I got all the pulling stuff off the engine. 

 

here is what it looked like

[Elkskin's mower junkyard 1,117]

1 hour ago, Joebag said:

 

here is what it looked like

take ur thumb press down on valves see if you can spin them. you shouldnt be able to spin them at top dead center. 

[artfull dodger 394]

You can get many of the special tools at Harbor Freight if you have one of those in your area.  Much cheaper.  You really need to get yourself a small tach to set the rpm correctly.  They are not real expensive.  I have one that I can put on the tractor and it will keep track of hours on the engine and the RPM whenever it runs.  Got it thru Briggs and Stratton. Has a wire you wrap around the plug wire to sense when its running and at what RPM.  The spark checker inline light also came from HF for 10 bucks.  Its not hard to rebuilt the small Kohler K series, they offer a nice service manual and it isnt expensive.  Takes you set by step if you choose to do your own work.  I can rebuild one, sans any machine shop work, in a single morning and break it in cutting grass that afternoon.  Many times just a hone, fresh rings and good cleaning and relapping of the valves is all thats needed.   Mike

[Shynon 7,459]

4 hours ago, artfull dodger said:

I have my compression tester, plug wrench on hand, and my spark testing light already on the plug.  Run it till she stalls, as she stalls, is there still spark(ie the light stil flashing as the engine shuts down), if not you have a ignition issue.  If spark remains as she shuts down, then as soon as the engine stops, remove the plug, install the compression gauge and crank the engine over ASAP

Just curious how do you get a compression reading on an ACR motor?

 

6 hours ago, Joebag said:

she will shut down once it is under a load

 

6 hours ago, Joebag said:

But the little shaft that the gov link is rideing on you know the one that you have to loosen the bolt in order to move the gov. backwards making sure the carb. is wide open. Well anyway it does not stop or tighten it only spins and spins  or turns and turns which everway you want to look at it.

The little tab on the inside of the motor which is attatched to the cross shaft is broken off, there for the shaft will just turn and turn and turn, so the gowernor will never engage under load and speed up the motor, thus it will die.

[Joebag 17]

I will have to pick me up some of those tools you wouldnt have a link for them would you

[artfull dodger 394]

You cant get a good true reading, but you can get close enough for an idea.  Kawasaki, which have an ACR in the newer engines to keep cranking till the gauge stops going up.  It used to be 3 to 4 puffs on a non ACR engine.  I believe a K181 is a non ACR engine.  And that is what I am believe is happening, the Gov isnt working, thus no balls under  load.  Tear down, inspect, hone and rering, repair/replace the Gov.   

[Joebag 17]

6 minutes ago, Shynon said:

Just curious how do you get a compression reading on an ACR motor?

 

 

The little tab on the inside of the motor which is attatched to the cross shaft is broken off, there for the shaft will just turn and turn and turn, so the gowernor will never engage under load and speed up the motor, thus it will die.

will it be an easy fix 

[artfull dodger 394]

I dont but for anyone doing thier own rebuilt work here is my short list.  Compression gauge, good set of feeler gauges, piston ring compressor to reinstall piston with rings into engine, piston ring install plyers, valve spring tool(its different for the old flat head VS OHV engines btw).  If your able to learn to read a Micrometer, then a couple of those to check bearings and the cylinder bore dimensions are good, and the Kohler service manual for K series engines.  I go thru Maple Grove Distributing in Galveston IN for my tools and parts.   Mike  P. S.   I repair small engines for a profession most of the time

Edited January 29, 2017 by artfull dodger

[Shynon 7,459]

When you tear the motor down, get a new or good used one and replace it. The whole motor needs to be disassembled to replace that.

[Joebag 17]

1 minute ago, Shynon said:

When you tear the motor down, get a new or good used one and replace it. The whole motor needs to be disassembled to replace that.

right, I am going to have afriend help me rebuild it. I am going to buy a ultimate rebuild kit $224.00

30 minutes ago, craftsmanmowerfreak said:

take ur thumb press down on valves see if you can spin them. you shouldnt be able to spin them at top dead center. 

the exhaust is alittle harder to spin then the intake when they both are open 

[artfull dodger 394]

Do it right and you will get another 20+ years of service out of that motor.  Also make sure you check over the carb as well, espically the bushing wear in the throttle butterfly shaft.  They tend to get really worn, allowing "false air" to get in around the shaft and making it run lean/hard or impossible to tune correctly.  They make an oversize bushing kit to fix that.   I stay away from stacks, but if you mod the exhaust, watch how much weight you put on the block.   I just run the stock "pepper pot" muffler on mine since its a worker and constant exhaust in the face when mowing sucks.   I cant wait to mow with my Horse. The JD212 I used last season had the turning radius of an ocean liner.  I think you can download that service manual over on Kohler's website if you have a good printer or a way to read it in the shop like on a tablet.  Mike P.S.   Very important and often missed even by seasoned techs.  Have your friend check the camshaft end play with a dial indicator or feeler gauge.  To much end play causes the cam to slap back and forth in the block  when running, causing that "Kohler Knock" that so many have, even after a complete and professional rebuild.  Also spark timing(controled by the point gap) can cause spark knock.  Do not always trust the book, wear on the plunger and camshaft can deviate from the book setting.  If it ran decent other than lacking power.  I would see what the point gap is now, and go back to that for the initial setting after the rebuild, then tune from there.      Good Luck

[Joebag 17]

5 minutes ago, artfull dodger said:

Do it right and you will get another 20+ years of service out of that motor.  Also make sure you check over the carb as well, espically the bushing wear in the throttle butterfly shaft.  They tend to get really worn, allowing "false air" to get in around the shaft and making it run lean/hard or impossible to tune correctly.  They make an oversize bushing kit to fix that.   I stay away from stacks, but if you mod the exhaust, watch how much weight you put on the block.   I just run the stock "pepper pot" muffler on mine since its a worker and constant exhaust in the face when mowing sucks.   I cant wait to mow with my Horse. The JD212 I used last season had the turning radius of an ocean liner.  I think you can download that service manual over on Kohler's website if you have a good printer or a way to read it in the shop like on a tablet.  Mike P.S.   Very important and often missed even by seasoned techs.  Have your friend check the camshaft end play with a dial indicator or feeler gauge.  To much end play causes the cam to slap back and forth in the block  when running, causing that "Kohler Knock" that so many have, even after a complete and professional rebuild.  Also spark timing(controled by the point gap) can cause spark knock.  Do not always trust the book, wear on the plunger and camshaft can deviate from the book setting.  If it ran decent other than lacking power.  I would see what the point gap is now, and go back to that for the initial setting after the rebuild, then tune from there.      Good Luck

I just got the horse in Dec. 2016, she has been like that since I have had her.

[Joebag 17]

Im in the process of making youtube vids of the rebuild here is the first vid https://youtu.be/YGb47j3nFt4  I will post more vids when I get the parts 

[Shynon 7,459]

53 minutes ago, artfull dodger said:

 I believe a K181 is a non ACR engine

k181 is an ACR engine. Need to do a leakdown test, compression test would not read properly

Edited January 29, 2017 by Shynon

[artfull dodger 394]

Ok, I couldnt remember, books are out in the garage.  The leakdown gauge setup isnt one of the cheaper tools to get.  It has to come apart to deal with the Gov issue, so a leak down is moot.  At this point, a full rebuild is best anyways due to the tear down to fix the Gov.  Went and got the book, all but the K91 had the ACR system in them.   Mike  

Edited January 29, 2017 by artfull dodger

[953 nut 55,316]

14 hours ago, Joebag said:

checked for slop on top of the piston, no movement an walls are as smooth as silk

As a rule the top and bottom of the cylinder do now have any wear, the center will. The cylinder wall being smooth as silk is not a good thing.

8 hours ago, Joebag said:

I am going to have afriend help me rebuild it. I am going to buy a ultimate rebuild kit $224.00

Don't buy any parts until it has been measured to see what size the crank and cylinder need to be machined to.

8 hours ago, artfull dodger said:

the Gov isnt working

Here is the best way to set your timing.

Kohler static_timing.pdf

[stevasaurus 22,764]

Joe, here is what that cross shaft looks like.  I'm holding it by the flag that the guys are saying broke off.  It's the right end that sticks out of the block.

 

In this picture, you can see the cross shaft and the flag up against the piston of the gear. 

 

 

Nice video Joe.