Kohler K-series ACR, Automatic Compression Release Overview

Here we look at the camshaft out of a K series Kohler engine and explain how the ACR works. Symptoms of a broken or missing ACR spring and and how it might be fixed.

[michaelsabin]

A concise and to the point video without a bunch of useless music or wanderings, Thanks!

[david]

Helpful? Man, I could hug ya' ! Thanks for the demo - my spring came off, too, and I just reached in and hooked it back up. I'd never have known why the thing wouldn't turn over without this video. Cheers from South Carolina!

[bobatbilletcreations]

I've been fighting with starting issues with this kohler of mine, I think this is my problem! You described it to a TEE! I have gone thru all the wiring, solenoid, Cables, Grounds ect, ect! I'm heading out to take off the cam cover! Thank you very much for taking the time to post this!

[StumperSteve]

Thanks so much!!! I had to replace my connecting rod and compression rings and afterwards the poor old girl would hardly turn over. I thought it was a weak battery but even with a fully charged battery it usually stuck on rolling over, I now know at the compression stroke. I took the cam cover off and a wee piece of metal was jammed in the ACR, I suspect from the broken connecting rod. I fished it out with a piece of wire and Bob's your Uncle, its back to easy starting. Again...Thx so much for posting this.

[tolbaszy]

Great video! My actuator tab appeared worn at first glance, but closer inspection showed the leading edge had been ground down. Replaced camshaft.

[wrx]

That exhaust tab on the cam is adjustable by bending it slightly with a screw driver. Lift it slightly to release compression. When engine starts the weights fly out allowing full compression.

[neilphilip]

Really well explained. I didn't realize my K141T had this so was mystified by this short valve "bounce" as I looked at the valve while turning the engine over. Initially I thought it could explain a frequent backfire through the exhaust - that must have a different cause unless the ACR can stick ? All seems free enough so I doubt it. But thanks for this!

[metalworksmachineshop]

I have a older k241 in my cub 100 the cam is in 2 pieces. Can you tell me how to install it back into the block.? Do I need another pin to put the cam together? Then tap it out with the cam pin for the block.. just guessing.. love the dozer build..

[bobbygetsbanned]

Does the ACR on the CH series work the same way? And if I understand correctly, the ACR wouldn't be a culprit for no compression situation since they fail in a way that keeps the compression?

[johnsbuilds]

I'm really hoping the spring is still there on mine and just off that tab

[johnnordquist]

Excellent video. My spring end was resting on camshaft. Thanks

[coldblazinfire]

Thank you sir. Great explanation of the system.

[timrussell]

My cub cadet with the courage 19 engine will barely crank now and not start. When it does crank you can clearly see compression blowing back up through the throat of the carburetor. I very strongly suspect that poorly engineered and extremely weak A.C.R system is the culprit. Thanks for really good vid!

[adventureguy]

Mine works half the time any idea what’s up

[rftrucker]

do you know where one could obtain a new spring?

[tonymontana]

Great engineering. They put the pissiest, most thinnest piece of wire there and hope it will last 2000hrs. Bloody hopeless these designers so called engineers. They think they know everything.