2010 craftsman 21hp wont crank more than 1 rev.

[trunkbuster]

I'm having the same trouble with my 31 series engine, it won't crank past compression. I've adjusted the valves to the recommended clearance while the piston was at 1/4 past TDC and also at TDC so I believe it's the compression release. The battery is good, I've tried two. It spins over just fine with the plug out and the oil level is ok. There is no gas in the oil. I couldn't find any posts on how to correct this problem. Does anyone have any experience correcting this issue?

 

[hrdman2luv]

I'm having the same trouble with my 31 series engine, it won't crank past compression. I've adjusted the valves to the recommended clearance while the piston was at 1/4 past TDC and also at TDC so I believe it's the compression release. The battery is good, I've tried two. It spins over just fine with the plug out and the oil level is ok. There is no gas in the oil. I couldn't find any posts on how to correct this problem. Does anyone have any experience correcting this issue?

It almost has to be the valves or the starter. Those are the only two ways (that I can think of) that would restrict the engine from turning over with the spark plugs still in. When one is out, there's no compression, and the starter turns the the flywheel freely.
I'd double check the valves/ Make sure you have the "top dead center" correct.

Your starter could be weak. But I'd bet it's the valves.

 

[ILENGINE]

When you are turning the engine over by hand and watching the valves open and close, do you see one of the valves bump off just before TDC.

 

[mechanic mark]

Post model xxxxxx, type xxxx, trim xx from engine. How did you adjust valves, procedure?

 

[hrdman2luv]

When you are turning the engine over by hand and watching the valves open and close, do you see one of the valves bump off just before TDC.

I just stick a screw driver into the spark plug hole, and gently turn the flywheel around a few times to make sure the valve I'm adjusting is where it's supposed to be, and the piston is all the way up...
Then after I've done that to both valves, I recheck them to make sure I didn't make a mistake.

 

[SeniorCitizen]

The compression relief cam bump can be checked with one of the least expensive tools on earth you already paid for and have. It's that feeler gauge set you set the valves with. If the cam bumps the valve as it should the 0.001 or 0.002 feeler gauge will tighten just before TDC. If the cam is shot the clearance you set ( 0.004 - 0.006 etc. ) will still be there through the compression stroke. Or you can go expensive and check the cam bump with a dial indicator.

 

[mechanic mark]

I just stick a screw driver into the spark plug hole, and gently turn the flywheel around a few times to make sure the valve I'm adjusting is where it's supposed to be, and the piston is all the way up...
Then after I've done that to both valves, I recheck them to make sure I didn't make a mistake.

Post craftsman model number from under seat. Did you adjust intake & exhaust valves before rotating engine?