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After help here with a head gasket diagnosis, I replace the gasket and adjusted the valves, but compression is so high. The engine will barely turn over unless I cover the intake. Pulled the crank case cover, and the camshaft and compression release is intact. I figured I made a mistake adjusting the valves, so after reassembly adjusted them again and compression is still far too high. I’m stumped. Any advice.? Thanks in advance.

There are 2 TDC strokes in a 4 stroke engine. Which one did you use?

Sounds like the ACR is not working. Temp gap the valves to 0.002" and see if the ACR works again.

Did you hand rotate the engine while checking the valves verifying your gap was proper?

Decarbonize the cylinder. It's in yours and every other small engine manual known to man.

slomo said:

There are 2 TDC strokes in a 4 stroke engine. Which one did you use?

Sounds like the ACR is not working. Temp gap the valves to 0.002" and see if the ACR works again.

Did you hand rotate the engine while checking the valves verifying your gap was proper?

Decarbonize the cylinder. It's in yours and every other small engine manual known to man.

Click to expand...

Yes, I got the valves at top dead center TDC

slomo said:

There are 2 TDC strokes in a 4 stroke engine. Which one did you use?

Sounds like the ACR is not working. Temp gap the valves to 0.002" and see if the ACR works again.

Did you hand rotate the engine while checking the valves verifying your gap was proper?

Decarbonize the cylinder. It's in yours and every other small engine manual known to man.t

Click to expand...

I don't see any ID numbers posted for the engine.
If it's a single cylinder Briggs Intek the valves are not adjusted at TDC per the manual specifications, go 1/4 inch down ATDC and set the intake valve at a snug .002 or even .0015 (as slomo says) and turn the engine over by hand few times CW with the spark plug out and monitor the INTAKE valve lash. (I've seen it go wider sometimes right after adjustments is why I say rotate the engine and re-check.
Next. You have to go slow and keep a good eye open for this. (this will let you SEE if the intake valve compression release is trying to dump/release any compression after you have set the INTAKE valve lash to a snug .0015-.002. Back the engine up backwards from TDC on compression stroke (CCW of the flywheel if looking down on a vertical shaft engine flywheel) to where the piston is going down by about 1/2 way (couple inches down) in the cylinder then slowly come up CW on the compression stroke and carefully watch the INTAKE valve's rocker arm for a slight dip in the rocker arm (it should dip down little bit then back up just before TDC) at about 1/4 to 1/2 inch before the piston reaches TDC. This dip in the rocker arm is the compression release momentarily slightly opening and dumping some of the compression by cracking open the intake valve just Before Top Dead Center (BTDC). You can monitor the position of the piston by using a long slim screwdriver into the spark plug hole. Just be sure you do not electrically crank the engine when the screwdriver is inserted.

Have you actually checked the compression? If not give us a compression reading from a gauge. (sometimes a weak electrical crank system will appear to be compression issues)Using another battery and good jumper cables will give you a hint about such. (also a weak starter can cause such) Placing the hand over the carb intake and getting a crank over is starving the engine of air so as to reduce the compression somewhat. This is what the ACR is suppose to do by slightly opening the intake valve and dumping some compression just before the piston reaches TDC.

You might also try cranking the engine over electrically with the spark plug wire off and the spark plug installed. If it cranks over with fire to the plug the timing is slightly too fast due to partly sheared flywheel key.
Also be sure the engine is not flooding and hydrolocking. Gas being spit out the spark plug hole is an indicator of such.

Mattdad1 said:

Yes, I got the valves at top dead center TDC

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On what stroke?

It just easier to adjust the rocker when the opposite rocker is fully the valve. Also the intake valve is the one closest to the oil pan.

What Slomo is trying to say is are you sure you set the valve lash on the compression stroke rather than the exhaust stroke
The "tests" is to check the valve lash at TDC twice
So set the lash, rotate the engine 1 revolution and check the lash
If it is bigger on the second check then you set the lash on the exhaust stroke not the compression stroke which is quite a common mistake when you use the TDC method , particularly when the cam is getting a bit old so the inlet opens a touch later & the exhaust closes a touch sooner .

Why do you think that the compression is too high ?

bertsmobile1 said:

What Slomo is trying to say is are you sure you set the valve lash on the compression stroke rather than the exhaust stroke
The "tests" is to check the valve lash at TDC twice
So set the lash, rotate the engine 1 revolution and check the lash
If it is bigger on the second check then you set the lash on the exhaust stroke not the compression stroke which is quite a common mistake when you use the TDC method , particularly when the cam is getting a bit old so the inlet opens a touch later & the exhaust closes a touch sooner .

Why do you think that the compression is too high ?

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Thanks all. Feeling stupid. Used the wrong valve clearance engine is running fine. Now just waiting for the ACR for the head gasket to fail again. What a crap design.. Thanks for the help!

Good to hear you got it going.
Read post #6 and get familiar with that procedure so as the next time you have to adjust the lash, just rotate the engine so as a valve's rocker arm is fully DOWN and then adjust the opposite rocker.

It's a no brainer and but we usually do not mention this procedure at first to a newbie because it is not ever mentioned in the Briggs engine SERVICE MANUALS.
You do not have to fool around trying to figure out if the piston and valves are on the TDC compression stroke.

On your model of engine after you adjust the lash turn the engine over 2-3 times without starting the engine and re-check the lash again BEFORE calling it good and installing the valve cover for a crank/run test because sometimes the valve lash will increase and just .002-.003 increase can result in compression lock again.

You are not alone most of us have done it at some time
Now go mow

Mattdad1 said:

After help here with a head gasket diagnosis, I replace the gasket and adjusted the valves, but compression is so high. The engine will barely turn over unless I cover the intake. Pulled the crank case cover, and the camshaft and compression release is intact. I figured I made a mistake adjusting the valves, so after reassembly adjusted them again and compression is still far too high. I’m stumped. Any advice.? Thanks in advance.

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Must be the compression release cam or bearing worn or bent. Make sure the valve actually raises b4 top dead center when turned slowly by hand.

doug9694 said:

Must be the compression release cam or bearing worn or bent. Make sure the valve actually raises b4 top dead center when turned slowly by hand.

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Thanks! It was (my) operator error. Valves were wrong. Running great now.

Saw this post due to my current situation and hope to find some answers. I have a cousin whose craftsman T210 started having starting issues. I brought it home and started to diagnose it. Everything pointed to bad ACR but the main thing that made me think of that was when you'd turn over the engine and it would stop at the compression stroke. Mower battery was bad (12v when key off then dropped to 6v when key was on, engine off) so I used my battery off my zero turn and it would turn over but eventually get weak ( i assume due to how long it was cranking) and stop at the compression stroke. Saw some YouTube videos that said if you have a bad ACR, cover the intake port and that will get you by, so I did that and the mower turned over fine and started. So since I work for a shop, I took the engine with me and tore it apart to verify the issue, but I did adjust the valves to make sure I wasn't forgetting anything. After removing closure plate (bucket engine) I removed the ACR and everything was fine. ACR moved freely and spring was still there. My cousin's husband did mention that when he tried to use the mower last time, he saw sparks come from the starter or in that area and when I had the engine on the mower, turning it over sounds like crap, like something was holding it back from turning it over smoothly. Engine model is KS40-3011, serial number 4904909253.
I still have the engine apart but am going to put it back together soon.

What is your question?
AND
You will get more replies if you will start your own post.

Just some general info you might consider:
From what you have indicated it appears that you need to put the engine back together, set the valve lash correctly and then when cranking do not crank over 5 sec's or the starter is going to smoke. Those starters are intermittent duty. Crank 5 seconds and then let it rest for awhile to cool down.
Then test with a known good battery. If you use a know good larger automotive type battery of 300CCA or more and it still cranks weak contact dbelectric and price a replacement starter or take your starter apart and check or bench check the running amps. You can finds lots of you tube info about Kohler starters.
It also appears that the engine is not starting correctly or fast so you may have additional issues when you get it cranking good.

Make sure the engine is not hydrolocking due to Raw gas on top of piston.

Forest#2 said:

What is your question?
AND
You will get more replies if you will start your own post.

Just some general info you might consider:
From what you have indicated it appears that you need to put the engine back together, set the valve lash correctly and then when cranking do not crank over 5 sec's or the starter is going to smoke. Those starters are intermittent duty. Crank 5 seconds and then let it rest for awhile to cool down.
Then test with a known good battery. If you use a know good larger automotive type battery of 300CCA or more and it still cranks weak contact dbelectric and price a replacement starter or take your starter apart and check or bench check the running amps. You can finds lots of you tube info about Kohler starters.
It also appears that the engine is not starting correctly or fast so you may have additional issues when you get it cranking good.

Make sure the engine is not hydrolocking due to Raw gas on top of piston.

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Sorry for the confusion and I saw this post and had the same issues going on so that is the reason I posted on this post. The question I have is the same as the original post, I have too much compression and after adjusting valves, I still have the same result. The battery I used from my zero turn runs 345 CCA and the battery that was originally on the mower runs less than 250 (don't have an exact number but it's less than 300 CCA). So, as I was under the assumption that the ACR was bad, I tore down the engine but the found ACR to be fine. I did check before teardown if engine would spin without spark plug in cylinder and it did. Thats when I blocked air going to the intake and started right up. Also, when the battery begins to get weak, you can eventually hear the solenoid start to whine or could be the starter. I guess the next thing to check would be electrical besides making sure valves are properly adjusted. I also did not see raw fuel in the cylinder so I doubt its locking up since I did get it to start.

I understand your why for post:
I was indicating you will get more tips and opinions about your Kohler if you do your own post. I'm not real familiar with that engine for hands on experience, just giving basics.
If you find a bad starter and need a replacement you might check with dbelectric.com to compare replacement prices. Some Kohler OEM replacements are costly.
I've had good luck with their replacement starters. Let them tell you which one you need.
Also on the Kohler starters you can usually get a brush repair kit that is easy to install, but make sure the bushings are ok first, especially the upper bushing. If it has any side slack the starter will drag.
You can find You tube videos about re-building Kohler starters.
Appears you need to do a open up for inspection of the starter before ordering a new one. I take a file or a sharp awl and put a witness mark on each end of things so as when re-assembling things you have alignment witness marks for more user friendly alignment of the bolts and end plates.
I have electrical testers that go to 400 amps DC that I use to help confirm testing of starter amps.
Some guys are lucky enough to have a old style starter/alternator re-build shop close by and they just take their starters to them for testing and repair.

Also make sure you are adjusting the valve lash PROPERLY per the SERVICE manual for that Model engine.

The previous guy had one of them wimpy/weak Briggs engines that can be a pain. (but his just needed a very close valve lash setting, sometimes has to be little bit below minimum specs on those type engines due to cam/valve train wear)

At least your engine is a better made Kohler.

StarTech said:

It just easier to adjust the rocker when the opposite rocker is fully the valve. Also the intake valve is the one closest to the oil pan.

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This is the poorest way to adjust valves on any engine and shows a total lack of knowledge of engine design and operation. It assumes the Intake & Exhaust cam lobes are 180° apart, when in fact they are only about 90° apart.



This means when one valve is fully open, the other valve is already on the approach to being opened. IOW, not at maximum slack as is required for valve adjustment.

They called it back in the day checking valve clearance on the heel of the cam. Making sure the valve you are looking at was on the back side or heel of the camshaft.

Whom ever, so many jumping in here. If you really have excessive compression, pull a head or two. Check for excessive carbon buildup on the head and behind the valves. Again this maintenance item is in EVERY engine manual just like some clean cooling fins. If a small chunk of carbon breaks off and gets into the cylinder bore, it will gouge the snot out of the bore. Carbon is some tough stuff. Look for de-carbonizing the cylinders in your engine manual. Usually like every 5-8 years??. More often if she drinks a little oil.

Also if your cyl head is packed with carbon, that carbon insulates the head and attenuates proper cooling.