Kohler Courage 19HP Single Cylinder High Compression Cranking

[DaveTN]

I don't have the model # handy, but this Kohler 19 Single, Twin Cam is on a Cub Cadet Riding Mower.
It will crank ok to a hard spot and will not go further without removing the flywheel
shroud and pull the flywheel through by hand. Once it's past the hard spot, you can
hit the starter and it will spin over and run. Is the compression release mechanism hard to
replace? I've seen some on E Bay for used cams and cam kits etc. The metal camshaft looks
to be one solid unit, cam and compression release combined. Will other single cylinder
cams interchange with the 19 single? I haven't pulled the top cover plate yet. Thanks!

 

[bertsmobile1]

I don't have the model # handy, but this Kohler 19 Single, Twin Cam is on a Cub Cadet Riding Mower.
It will crank ok to a hard spot and will not go further without removing the flywheel
shroud and pull the flywheel through by hand. Once it's past the hard spot, you can
hit the starter and it will spin over and run. Is the compression release mechanism hard to
replace? I've seen some on E Bay for used cams and cam kits etc. The metal camshaft looks
to be one solid unit, cam and compression release combined. Will other single cylinder
cams interchange with the 19 single? I haven't pulled the top cover plate yet. Thanks!

First forget about the bold type.
Second start with the easy bits first.
Check the valve lash.
If and only if you can not get them to spec think about pulling the top plate.
Download your service manual from the link below and read yourself rich.
"K&T Parts House Lawn Mower Parts and Chain Saw & Trimmer Parts"

 

[mwrman]

I agree with checking the valve lash. I have seen this before.

 

[DaveTN]

Update: I checked valve lash and it was within specs. I pulled the lid on it
and inspected both cams, esp the Ex Cam and the Compression Release Device.
I took it to the repair shop thinking that it was jamming up as it appeared to be,
but told that it was working as it should by two mechanics working there. I put
the Exhaust Cam and Compression Relief back together and installed it. Did not
bolt the lid on but only pulled it through. Still same thing: Pull it through and
watch the cams and push rods work both Intake and Exhaust Valves and then hit a hard
spot with High Compression! I had to put a ratchet and socket on the bottom pulley
and pull it past the hard spot just as it was before. Any ideas guys?

 

[bertsmobile1]

Pull the plug and watch the valves very carefully as you rotate the engine.
the inlet should close then open just a little before the piston gets to TDC.
If not halve the lash on the inlet valve and try again.
No joy, take out the cam and check the end of the shafts for wear, shaft for straitness and cam for wear.
Check the holes in the case & top plate for wear also check that the dowels are in place on the top plate.

 

[DaveTN]

Pull the plug and watch the valves very carefully as you rotate the engine.
the inlet should close then open just a little before the piston gets to TDC.
If not halve the lash on the inlet valve and try again.
No joy, take out the cam and check the end of the shafts for wear, shaft for straightness and cam for wear.
Check the holes in the case & top plate for wear also check that the dowels are in place on the top plate.

Update: Checked valve clearances and reset the correct 'valve lash' according to Kohler specs. Did what you
asked me to do and yet no change. It is still doing the same thing it did originally. Even varied the lash up
and down a few thousands on both Intake and Exhaust valves to see if it made any difference. Nothing. Still having
high compression on cranking. This engine will run when you 1st pull it manually past the high compression spot, then
hit the starter and it will spin over and fire off and run. Idles good, throttles up well, wide open fine as well. Governor
works fine. I checked the ACR unit and it is moving the Exhaust Valve as well, so it appears to be working. I can not
understand why the engine is holding such high compression if it (ACR) is working. Starter is in good shape and works with a
fully charged battery. It is acting like a 'problem child' and I am getting tired of it after a week's worth of tinkering with
it and no success. Any more ideas as to what to try? Thanks.

 

[gainestruk]

Like bertsmobile1 said next check cam for wear, the ends where cam goes into block and cam lobes for wear, even if it appears the acr opens valve the lobe might be worn enough that it doesn't open enough to release compression.

 

[DaveTN]

Update: I switched out both Intake and Exhaust Cams, push rods, and ACR
(Automatic Compression Release)...to no effect! I talked to 2 Master mechanics and they
walked me through the correct procedures and said that I had done all I could with it
and they couldn't think of anything else to try except to replace the starter. Do they
make a high torque starter that could be switched out with the regular starter? One that
would be able to spin it through the high compression cycle?

 

[bertsmobile1]

Start by confirming that then engine spinns freely without any compression, plug removed.
If this is the case
Normally the ACR is on the inlet valve not the exhaust so check by turning the engine over slowly by hand.
You should be able to see the rocker push the valve open and hear the gasses rushing out.
If not close down the clearence on whichever valve has the ACR on it till it does what is mentioned above.
If you can not get it to behave as mentioned then some thing is stopping the ACR working.
Most likely candidates are worn cam bushes
Worn cam
Worn cam followers

Now push a stick against the piston & rotate the engine feeling for tight spots.
A bent valve will also cause hard cranking

 

[DaveTN]

Update: Just as an experiment I tried the ACR switched to the Intake Cam
all to no avail. I am going back to work on it again today after some other
weedeater repairs first. At the point now of trying to find a High Compression
Starter that has the torque to push it on through the compression hard spot!
I am going to switch out a known good starter from a 15 HP Single Kohler
Command and see if it makes any difference. Going back together with it
today as I have done all I know internally with cams, push rods, valve lash,
ACR, etc. More later on this starter switch later. I was told that the current
starter on it was rebuilt and good. Cranks over good with the spark plug out.
And fairly good with the plug in till it hits the high compression spot, then
locks down and that's it till I pull it through the cycle. Once pulled through the
High Compression spot, the starter will spin it and it'll fire off and run well.
Wish me luck! :thumbsup: