B&S help.

[Buckshot 1]

I have in my shop a Craftsman LT with the following engine, 31C700231-E1, SN: 030806ZE. When trying to start it, when it comes up on the compression the engine will no longer spin/turn. Battery is showing 13.7V. I put my battery charger on boost and sprayed a little starting fuild in the carb. All I got was a big backfire thru the carb. while trying to start it. The owner did state that he put a set of rings in this engine. The valves were out of adjustment, which I corrected, but I am still getting the same results. I am thinking that when he was inside this engine, he either has the cam timming off or he screwed up the ACR. I have not worked on many OHV engines, I appreicate some ideas/suggestions on this problem. Thank you for your time.

[bgsengine]

quickest and easiest would be to do a compression test, and also see how it spins with plug out.

compression around 80-90 PSI, ACR OK and the problem is likely starter, hydro locked engine, or poor electrical connections

High compression means either ACR or valve adjustment was done wrong.

When rolling it over by hand, see if one of the valves "pops" a little bit just after intake valve closes. also make sure you actually adjusted the valves in the right spot - engine to TDC then roll until piston is down 1/4" past TDC

[Deere2me]

:) I have in my shop a Craftsman LT with the following engine, 31C700231-E1, SN: 030806ZE. When trying to start it, when it comes up on the compression the engine will no longer spin/turn. Battery is showing 13.7V. I put my battery charger on boost and sprayed a little starting fuild in the carb. All I got was a big backfire thru the carb. while trying to start it. The owner did state that he put a set of rings in this engine. The valves were out of adjustment, which I corrected, but I am still getting the same results. I am thinking that when he was inside this engine, he either has the cam timming off or he screwed up the ACR. I have not worked on many OHV engines, I appreicate some ideas/suggestions on this problem. Thank you for your time.

That's what I'm thinkin'...

[Buckshot 1]

quickest and easiest would be to do a compression test, and also see how it spins with plug out.

compression around 80-90 PSI, ACR OK and the problem is likely starter, hydro locked engine, or poor electrical connections

High compression means either ACR or valve adjustment was done wrong.

When rolling it over by hand, see if one of the valves "pops" a little bit just after intake valve closes. also make sure you actually adjusted the valves in the right spot - engine to TDC then roll until piston is down 1/4" past TDC

Thank you for your reply. The engine spins great with the plug out. tried to do a compression test, when it came up on compression the engine stop turning and the gage showed 40psi. I adjusted the valves like you stated. No gasoline smell on the dip stick, I had to add 10 oz's of oil before I even tried to start it. I will check the electrical connections and bench test the starter. If you have anymore ideas/suggestions, I will appreciate them. Thank you for you time. .

[Buckshot 1]

:) I have in my shop a Craftsman LT with the following engine, 31C700231-E1, SN: 030806ZE. When trying to start it, when it comes up on the compression the engine will no longer spin/turn. Battery is showing 13.7V. I put my battery charger on boost and sprayed a little starting fuild in the carb. All I got was a big backfire thru the carb. while trying to start it. The owner did state that he put a set of rings in this engine. The valves were out of adjustment, which I corrected, but I am still getting the same results. I am thinking that when he was inside this engine, he either has the cam timming off or he screwed up the ACR. I have not worked on many OHV engines, I appreicate some ideas/suggestions on this problem. Thank you for your time.

That's what I'm thinkin'...

Deere2me, Thank you for your reply.

[bgsengine]

quickest and easiest would be to do a compression test, and also see how it spins with plug out.

compression around 80-90 PSI, ACR OK and the problem is likely starter, hydro locked engine, or poor electrical connections

High compression means either ACR or valve adjustment was done wrong.

When rolling it over by hand, see if one of the valves "pops" a little bit just after intake valve closes. also make sure you actually adjusted the valves in the right spot - engine to TDC then roll until piston is down 1/4" past TDC

Thank you for your reply. The engine spins great with the plug out. tried to do a compression test, when it came up on compression the engine stop turning and the gage showed 40psi. I adjusted the valves like you stated. No gasoline smell on the dip stick, I had to add 10 oz's of oil before I even tried to start it. I will check the electrical connections and bench test the starter. If you have anymore ideas/suggestions, I will appreciate them. Thank you for you time. .

if it cant turn over enough to do a compression test, you got a starter or electrical problem either as a primary cause, or in addition to over-compression.

13.7v at battery? I'd be checking my test meter, or have the battery load tested.. A fully charged battery standing by itself should only register 12.8 volts (One wonders what cranking Voltage might be when you measure voltage at the starter terminal while trying to crank engine over...)

could have a bad ground connection (seen plenty of those) , could have a weak or failing battery, could have a bad connection (voltage drop) anywhere in the crank circuit.. I'd check and fix those first before assuming you have a high compression issue.

[bobodu]

Don...did you make sure that piston was PAST TDC? It you didn't....it ain't right. In fact...you can tighten up those valves to near zero lash and see if that improves things. Had one years ago that I had to do that too. New cam and everything....never did figure it out.

[Buckshot 1]

I apologize for the delay in relying, but my shoulder is acting up again (frozen shoulder) and I have been going to PT for the past week. I took Bob's suggestion and reset the valves to .003. I charged the battery to 13.5V, yes I did a load test on the battery and it is ok. Guess what she spins over
Also checked the compression with two different gauges and it is 145 psi. Will not start, no gas getting to the spark plug. Checked the fuel solenoid and it is getting power, thats not saying that the needle is going up and down. I still think this engine is out of time, as I gave it a shot of ether and it back fired.

[Mek-a-nik]

Can you see the ACR operating?
Is the crankshaft key sheared?
If both are okay, maybe you'll have to pull the sump cover to verify cam to crank timing.
As to the 13.5 volts, are you checking the voltage right when you disconnect the charger? The battery needs some time to "settle" before you can get an accurate reading.

[Buckshot 1]

Can you see the ACR operating?
Is the crankshaft key sheared?
If both are okay, maybe you'll have to pull the sump cover to verify cam to crank timing.
As to the 13.5 volts, are you checking the voltage right when you disconnect the charger? The battery needs some time to "settle" before you can get an accurate reading.

Mek-a-nik, how you been. fine I hope. No can not see the ACR, Crankshaft key is where it suppose to be. Pulling the engine and then the sump is going to be my next move. Battery set over night before I put it back in the tractor.