GCV 160 defies my repair attempts

[Jimel]

This engine is on my logsplitter, probably has some 150 hours on it. It was running fine until I tried to use it recently. It started fine as usual, but after a minute it quit. Started right up again, ran for a minute normally then died again, suddenly, as if fuel was lost. I began by making sure the fuel was fresh and reaching the carburetor. I then cleaned the carb per you-tube tutorials, twice. No change. So I bought a new carb and installed with new gaskets. No change. Started but died after a minute or two. Decided to check out everything else I could think of. Coil was checked and clearance reset, though it seemed very close. When I checked the valves, lash was good but exhaust valve was broken. It closed the valve but was weak. I thought aha! and ordered and installed new spring and reset lash. No change. Checked compression by cranking 3-4 times on my guage screwed into spark plug hole. It was 71# which I believe is good. I tried this several times to be sure. The governor seems to be working fine, and I checked that that little adjustment was fully to clockwise position. Oil is fresh and full. I tried unhooking the kill switch wire from the coil but no change. I tried removing gas cap while it ran to make sure cap was breathing. No help.
Last attempt was yesterday. It actually ran for 3-4 minutes so I threw a log on and the moment the blade touched the log it died, apparently did not like the load. However, it started right up again, ran a few minutes and died. I am ready to give up without new ideas, and buy a new engine for it. Hoping to avoid that as it seems to be basically ok and I may just be missing something.
Sorry for such a long post but wanted to be clear about what has been tried already.
Thanks in advance for any ideas.

 

[Jimel]

This engine is on my logsplitter, probably has some 150 hours on it. It was running fine until I tried to use it recently. It started fine as usual, but after a minute it quit. Started right up again, ran for a minute normally then died again, suddenly, as if fuel was lost. I began by making sure the fuel was fresh and reaching the carburetor. I then cleaned the carb per you-tube tutorials, twice. No change. So I bought a new carb and installed with new gaskets. No change. Started but died after a minute or two. Decided to check out everything else I could think of. Coil was checked and clearance reset, though it seemed very close. When I checked the valves, lash was good but exhaust valve was broken. It closed the valve but was weak. I thought aha! and ordered and installed new spring and reset lash. No change. Checked compression by cranking 3-4 times on my guage screwed into spark plug hole. It was 71# which I believe is good. I tried this several times to be sure. The governor seems to be working fine, and I checked that that little adjustment was fully to clockwise position. Oil is fresh and full. I tried unhooking the kill switch wire from the coil but no change. I tried removing gas cap while it ran to make sure cap was breathing. No help.
Last attempt was yesterday. It actually ran for 3-4 minutes so I threw a log on and the moment the blade touched the log it died, apparently did not like the load. However, it started right up again, ran a few minutes and died. I am ready to give up without new ideas, and buy a new engine for it. Hoping to avoid that as it seems to be basically ok and I may just be missing something.
Sorry for such a long post but wanted to be clear about what has been tried already.
Thanks in advance for any ideas.

Not long enough? here's more:
Forgot to mention spark plug is clean, dry and gapped to spec. Also, I had not rechecked the compression after the new spring. I just did and it went up to 80.
I remembered too that I have an old walk-behind mower that I no longer use. I just looked and it has GCV 190. Only difference I see with a glance is the auto ckoke-off. Mounting holes seem the same and the shaft is the same length as far as I can tell without disassembly. Any reason I could not switch it over if needed?

 

[ILENGINE]

Replace the spark plug and retest. Plugs do weird things especially on Honda engines. And I have seen this exact symptom on Honda engines half a dozen times with faulty plugs. And if you do decide to swap the engine make sure the flywheel is the same. Most likely the 160 has a heavy cast flywheel and the 190 is aluminum light flywheel.

 

[Hammermechanicman]

Ditto on the spark plug. I have also seen multiple Honda engines do that exact thing and a new plug fixed it.

 

[Jimel]

Ditto on the spark plug. I have also seen multiple Honda engines do that exact thing and a new plug fixed it.

Thanks for the quick response. Intermittent plug function was on my mind but I live off the road system in a small village in Alaska and getting anything can be a process. I ordered a new plug last week but still waiting.
I will be thrilled if this does it. If so it should run really well now all tuned up.
I just looked at the plug in the mower engine and it is an NGK BPR5ES. Plug in the GCV 160 is a BPR6ES. Nose length is same so probably safe but will the 5ES perform ok in the 160?

 

[ILENGINE]

Thanks for the quick response. Intermittent plug function was on my mind but I live off the road system in a small village in Alaska and getting anything can be a process. I ordered a new plug last week but still waiting.
I will be thrilled if this does it. If so it should run really well now all tuned up.
I just looked at the plug in the mower engine and it is an NGK BPR5ES. Plug in the GCV 160 is a BPR6ES. Nose length is same so probably safe but will the 5ES perform ok in the 160?

One notch hotter plug. Use it.

 

[Tiger Small Engine]

One notch hotter plug. Use it.

If plug doesn’t solve issue, check low oil shut off.

 

[ILENGINE]

If plug doesn’t solve issue, check low oil shut off.

Never saw one used on a GCV160 lawnmower style engine. GX and GXV yes, but not the GC and GCV series.

 

[StarTech]

Kinda sounds like a failing ignition coil to me.

 

[Jimel]

Good news update:
The new spark plug arrived this AM. I put it in and it is operating normally again.
I would have tried new coil next. This series, as noted, does not have a low oil switch.
A note on spark plugs. I noticed last night the GCV 160 manual says that the BPR5ES is for pressure washers, and all other applications take BPR6ES. So since my unit has had the "wrong" plug since day one I guess in this instance they are pretty much interchangeable.
I really appreciate all the help, thanks again and may you all have a good Christmas holiday.