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Hard starting Kohler

#1

B

Blackstar

Hello. I've owned this Cub Cadet 1320 Hydro for 7 or 8 years. It's an early 70's model, from what I can find out about it. It has always had this quirk that when warmed up and I try to restart the engine barely moves and seems to come up on compression and just stops dead. New battery last year and it still does this. The other day I was moving firewood with the Cub pulling my 10 yd wagon and when I tried to restart it acted up again. Usually after 3 or 4 tries it will turn over normally and start and run normal. But this time I kept trying until I took out the solenoid. Now have to start it with a screwdriver across the points until I get a chance to pick up a new solenoid.

I was told that my valves may need to be adjusted because the exhaust isn't opening enough or quick enough to release the compression. Also was told that the compression release could be worn. Didn't know it had a compression release. Any ideas on which direction to take this?

Thank you for any help...

Glenn


#2

B

Blackstar

After a little investigating, I find that part of the model number from the engine tag is missing. Serial number is B141G2, Spec number is 1211. Model number looked to me to be EV 55 at first but there's no such number on their site.


#3

B

bertsmobile1

What you are seeing is classic decompression failure.
Remove the rocker cover and adjust the valve lash as per the manual you will find in the link below.
Depending upon our model it may decompress on either the inlet or exhaust.
To check it you first adjust the valve lash then poke a skewer down the plug hole then watch the rockers.
Just before top dead centre either the inlet or exhaust will open a tiny amount this is the decompression.
http://www.mymowerparts.com/pdf/Kohler-Service-and-Repair-Manuals/


#4

I

ILENGINE

The the spec number he posted he has the CV125s which uses hydraulic lifters, so no adjustment and the Command doesn't use decompression so that wouldn't be a cause either. So maybe lifter bleeding off and effecting the valve open timing slightly cause too much compression, or possible something cause excessive compression. I am curious what the actually compression is.


#5

B

Blackstar

bertsmobile1 said:
What you are seeing is classic decompression failure.
Remove the rocker cover and adjust the valve lash as per the manual you will find in the link below.
Depending upon our model it may decompress on either the inlet or exhaust.
To check it you first adjust the valve lash then poke a skewer down the plug hole then watch the rockers.
Just before top dead centre either the inlet or exhaust will open a tiny amount this is the decompression.

Thanks for the input Bert...
Click to expand...


#6

B

Blackstar

ILENGINE said:
The the spec number he posted he has the CV125s which uses hydraulic lifters, so no adjustment and the Command doesn't use decompression so that wouldn't be a cause either. So maybe lifter bleeding off and effecting the valve open timing slightly cause too much compression, or possible something cause excessive compression. I am curious what the actually compression is.
Click to expand...

But wouldn't a bad lifter finally quit working? This has been ongoing for 7 -8 years...


#7

B

Blackstar

Blackstar said:
bertsmobile1 said:
What you are seeing is classic decompression failure.
Remove the rocker cover and adjust the valve lash as per the manual you will find in the link below.
Depending upon our model it may decompress on either the inlet or exhaust.
To check it you first adjust the valve lash then poke a skewer down the plug hole then watch the rockers.
Just before top dead centre either the inlet or exhaust will open a tiny amount this is the decompression.

Thanks for the input Bert...
Click to expand...

And thank you for the link to the service manual. :)
Click to expand...


#8

I

ILENGINE

Blackstar said:
But wouldn't a bad lifter finally quit working? This has been ongoing for 7 -8 years...
Click to expand...

it could be bleeding off, but actually may not be bad in like stay collapsed causing a constant tapping sound. Do you get a tap tap tap at startup.


#9

B

Blackstar

ILENGINE said:
it could be bleeding off, but actually may not be bad in like stay collapsed causing a constant tapping sound. Do you get a tap tap tap at startup.
Click to expand...

Nope. Mostly quiet engine.


#10

reynoldston

reynoldston

Before you do anything make sure it isn't in the electrical system. cables, grounds, connections, bad starter bushings, etc. A bad carbon build up on top of the piston maybe?


#11

B

Blackstar

reynoldston said:
Before you do anything make sure it isn't in the electrical system. cables, grounds, connections, bad starter bushings, etc. A bad carbon build up on top of the piston maybe?
Click to expand...

Will do.


#12

Scrubcadet10

Scrubcadet10

Could be the bump on the ACR is getting worn, too?!


#13

B

Blackstar

Scrubcadet10 said:
Could be the bump on the ACR is getting worn, too?!
Click to expand...

ACR?


#14

Scrubcadet10

Scrubcadet10

Auto Compression Release on the camshaft. lets the compression out making it easier to start until the engine has started. There is a little bump on the release that rides on exhaust lobe of the cam, which lets the compression out whenever its turning over. Usually they fall apart before the bump wears out, but you never know. More than likely its not tho.'
:2cents:


#15

B

Blackstar

Scrubcadet10 said:
Auto Compression Release on the camshaft. lets the compression out making it easier to start until the engine has started. There is a little bump on the release that rides on exhaust lobe of the cam, which lets the compression out whenever its turning over. Usually they fall apart before the bump wears out, but you never know. More than likely its not tho.'
:2cents:
Click to expand...

Gotcha... Thanks


#16

B

Blackstar

I'm back. The old Cub Cadet has been working pretty good. The hard starting problems didn't occur nearly as much. Until recently.
The reason I'm here today is because I'm still confused on whether or not I can adjust my valves. According to the service manual
there is either adjustable or non adjustable valve lash.


#17

B

Blackstar

I'm hoping someone's reading these. Pulled the plug and the motor spins freely. Starter seems ok. I took the valve cover off and looks like I have non-adjustable valves. Rocker bridge type.


So, I don't even know if I have automatic compression release.


#18

S

SidecarFlip

bertsmobile1 said:
What you are seeing is classic decompression failure.
Remove the rocker cover and adjust the valve lash as per the manual you will find in the link below.
Depending upon our model it may decompress on either the inlet or exhaust.
To check it you first adjust the valve lash then poke a skewer down the plug hole then watch the rockers.
Just before top dead centre either the inlet or exhaust will open a tiny amount this is the decompression.
http://www.mymowerparts.com/pdf/Kohler-Service-and-Repair-Manuals/
Click to expand...

Every Kohler ever produced has an internal compression release on the cam shaft that is dependent on valve las setting to operate correctly. Even my 20 year old K241 single cylinder slugger on me gas welder has the CR. Nice thing about it is when I start it, I can hear the compression release close up. It changes running pitch and looses the telltale clicking the decompression lobe makes.

You need to adjust the valves. Kohler engine manuals are available online for download.


#19

B

Blackstar

SidecarFlip said:
Every Kohler ever produced has an internal compression release on the cam shaft that is dependent on valve las setting to operate correctly. Even my 20 year old K241 single cylinder slugger on me gas welder has the CR. Nice thing about it is when I start it, I can hear the compression release close up. It changes running pitch and looses the telltale clicking the decompression lobe makes.

You need to adjust the valves. Kohler engine manuals are available online for download.
Click to expand...

I read through the section in the manual and it states there are three different arrangements of the rockers. Mine is the rocker bridge type. Both rockers pivot on a rocker pin. I can't see anything to adjust.


#20

S

SidecarFlip

Sounds the same as as the K241 I have. They way you adjust the clearance on my engine is grind the ends of the valve stems where they contact the lifters. They have to be ground square the the stem and it entails removing the head (s) and renewing the head bolts and head gasket(s). The way you obtain the clearance is use a feeler gauge to check the clearance you now have, remove the head(s) and pull the valves and remove enough material to get the overall length of the vale within the tolerance you require. It's not a bad job but will require you to have a valve spring puller (C) tool, torque wrench and some time.

The only way to check the the ACR is operating correctly is to pull the cam which is in the belly of the engine but I think you have excessive clearance in the valve train.


#21

S

SidecarFlip

Far as the tapping goes. mine 'taps' too until I increase the RPM and then the ACR deactivates and it's quiet as a mouse. The tapping is the ACR sub cam attempting to hold the valve (intake or exhaust) off the seat by a few thousands and if it taps, it's working fine so you have a valve clearance issue (excessive). The ACR cannot hold the valve off the seat if the clearance is too great.. That is why you have a hot start issue. Lots of compression and quick ignition but no ACR so the motor cannot get past TDC and roll over.

If you feel incapable of removing the valves, any competent shop can handle it.

If you do it yourself, I'd de-carbonize the head (which Kohler recommends anyway every 500 hours) and check the valve seats while you have the valves out. Seats and valves are easy to lap when it's apart.

Make sure you install new head bolts and a head gasket. Head bolts are much cheaper at Fasten-All versus the mower shop. Head gaskets are online at Amazon.


#22

B

Blackstar

SidecarFlip said:
Sounds the same as as the K241 I have. They way you adjust the clearance on my engine is grind the ends of the valve stems where they contact the lifters. They have to be ground square the the stem and it entails removing the head (s) and renewing the head bolts and head gasket(s). The way you obtain the clearance is use a feeler gauge to check the clearance you now have, remove the head(s) and pull the valves and remove enough material to get the overall length of the vale within the tolerance you require. It's not a bad job but will require you to have a valve spring puller (C) tool, torque wrench and some time.

The only way to check the the ACR is operating correctly is to pull the cam which is in the belly of the engine but I think you have excessive clearance in the valve train.
Click to expand...


That sounds like an off season repair job for me. But anyway, I was just back out to the shed and checked if the ACR was working by rotating the engine through it's cycles and just as the intake valve closes the exhaust valves opens slightly then closes again. So this means I have to pull the head?

While I was checking things I noticed that the rockers and pushrods seem very snug. No loose play in anything. Feels like the lifters are pumped up correctly...


#23

S

SidecarFlip

The lifters are solid, not hydraulic. The flat end rides the camshaft, the hollow end is where the pushrod fits into. You need to roll the engine over to TDC with both valves closed to check the clearance. Use a dowel rod in the sparkplug hole to determine TDC. Remember is's a 4 stroke so you may have to roll it over 2 revolutions.


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