[dengebre]

I have a John Deere LA145 (B&S Engine 441777-0116-E1, 22hp) that will not turn over. The starter engages and the flywheel will move a fraction of a turn and then stops. After that I can hear clicking if I try to start it again, but the flywheel does not budge. I can turn the flywheel a full revolution by hand but if I try to start it again the same thing happens. I just replaced the starter (thinking that was the problem), the solenoid is fairly new, the battery is charged, the carburetor was just cleaned, and the fuel lines and filter are new.

I saw a video where a similar engine would not turn over because it got stuck on compression. Apparently, there is a flywheel on the camshaft that sometimes breaks. Does this sound like the cause of my problem or is it something else? Am trying to get a gut-check before I tear the engine apart.

 

[Sundancer268]

Have you checked both ends of BOTH battery cables, pulling on them to verify there is no hidden corrosion and the connection is clean and bright? I would also verify the voltage at the starter terminal when you try and start the engine. You could have a bad battery that no longer can supply the necessary amperage to the starter. You can check this by measuring the battery voltage at the battery terminals while again cranking engine. Check at the termkinals and again at the cable clamps.

 

[jgayman]

It sure sounds like a broken compression release mechanism but first do as the previous poster suggested and check the voltage AT the starter terminal while attempting to crank the engine.

You can also try rotating the engine by hand just past the compression stroke and then try the starter. When my compression release broke I was able to start it by this method. Also, most folks say if you take the air cleaner off and hold your hand over the intake tube you can get it to start. This lessens the air and reduces the compression force.

The automatic compression release can also fail to operate if the valves are out of adjustment.

Try the steps above and let us know the result.

 

[RadarDon]

I would think a quick check on compression release would be to remove the spark plug without changing anything else. If it spins freely that might be an indication. Weak battery or poor connections could also make it stop turning when the turning gets hard. I've had a dirty starter cause the same symptom but you changed that.

I ran afoul of several Kohler single cylinder engines and broken compression release springs were one of their problems.

 

[dixie460]

Start with the easy stuff first...

Worked on an LA120 with a Briggs v twin that acted this way. All I did was adjust the valves to spec and it spins over like brand new.

 

[jgayman]

Start with the easy stuff first...

Worked on an LA120 with a Briggs v twin that acted this way. All I did was adjust the valves to spec and it spins over like brand new.

While seemingly simple, not everyone is comfortable adjusting the valves. There are a few basic steps above that should help determine if the issue is ACR related. If it is, then the only remaining question is if it's valve adjustment related or is the ACR broken. I've had to replace the cam twice on my 31000-series engine due to the delicate ACR mechanism.

 

[dixie460]

What really sucks is that the whole reason the compression release is there in the first place is as a cost saving measure. With ACR the manufacturer can get away with a smaller starter, lighter battery cables and smaller battery.

On an engine with rope start I can see a benefit to it, but if the sole means of cranking is an electric motor I'd rather pay more for beefier starter.

 

[99f250]

What really sucks is that the whole reason the compression release is there in the first place is as a cost saving measure. With ACR the manufacturer can get away with a smaller starter, lighter battery cables and smaller battery.

On an engine with rope start I can see a benefit to it, but if the sole means of cranking is an electric motor I'd rather pay more for beefier starter.

I agree 100% 😭🤬

 

[dengebre]

It surely sounded like the ACR was the issue and the video I found showed it as a “toggle weight” on the camshaft that sometimes breaks. Was I surprised to pull the engine apart only to find that there is no such item attached to the camshaft. As far as I can see there isn’t anything resembling an ACR.

I will be reassembling the engine this weekend. Any thoughts on how to proceed next? Again, I just replaced the starter, the solenoid is fairly new, the battery is charged (reading 13v).

 

[dixie460]

Well since you disassembled it, now you'll HAVE to check the valve lash. So do that and try starting it first. It will likely fire right up.

If not then check your wiring, check battery voltage at the starter WHILE cranking, and if that's all good, I'd look hard at that new starter. Remember, just because a part is new does not necessarily mean it's good.

 

[jgayman]

It surely sounded like the ACR was the issue and the video I found showed it as a “toggle weight” on the camshaft that sometimes breaks. Was I surprised to pull the engine apart only to find that there is no such item attached to the camshaft. As far as I can see there isn’t anything resembling an ACR.

I will be reassembling the engine this weekend. Any thoughts on how to proceed next? Again, I just replaced the starter, the solenoid is fairly new, the battery is charged (reading 13v).

Some B&S 2-cylinder engines have a "Easy Spin" cam grind which holds the Intake Valve open well into the compression stroke to relieve compression. Valve clearance adjustment is critical for this to work properly.