Allis B engine

Ok I finished installing my woods mower and test drove it. It does a nice job. But one time around the yard and the engine started to bog down and died. It starts right up, but runs well for about 8 or 10 minutes and then bogs down and dies. This time it seemed to be really tight, the starter would hardly turn it over. I tried the hand crank I could turn it but it was tight. I pulled the spark plugs to see if water was in the cylinders , they were all dry. I started it back up and ran it about half throttle and it would run for ever.
I locked the clutch so it was disengaged and no difference.
I suppose next thing to do is clean the main jet in the carb by running a stiff wire through it.
But why is it getting hard to turn over? The oil pressure and water temperature was normal.
John

Thanks Steve, never thought about it getting hot since the temperature gauge was a little below normal. I’ll check water movement with the radiator cap off

Steve, I let the tractor sit for about 2 hours to watch the eclipse. So I started it up , was going to take it behind the garage to remove grill etc to flush it out and I decided to put the mower in gear. I mowed for about an hour, didn’t miss a bit. I wonder if dirt in carb.
Anyway I’m still going to flush the radiator and block. Would it be worth it to put radiator cleaner in it before flush?

Anyway I’m still going to flush the radiator and block. Would it be worth it to put radiator cleaner in it before flush

that gauge wont read if it doesnt have water surrounding the probe

There are 3 frost plugs on the oil filter and distributor side. Would it be possible to remove those to better clean the muck out of the block? I assume you can buy them at a napa store

Removing the frost plugs would definitely give you good access for sure,, you would still want to hit it with a pressure washer (a garden hose nozzle may not be enough), if it would be as bad as mine. On one block I had good success putting the pressure washer nozzle down the cooling holes on the top of the block and having it drain out the side of the block. The advantage with your idea of popping one or several frost plugs is leaving the top of the engine untouched.

Those 3 soft plugs only allow access to the lifters and pushrods. If you really want to clean the block you need to completely dis-assemble the block. You  can do a reasonable job by only removing the head with lots of digging down through the holes and compressed air.

PaulB wrote: Those 3 soft plugs only allow access to the lifters and pushrods. If you really want to clean the block you need to completely dis-assemble the block. You  can do a reasonable job by only removing the head with lots of digging down through the holes and compressed air.

Yes after looking at different pictures, I discovered that. Getting a bit chilly and raining here for the next week or so. When it warms up a bit, I’ll drain and flush it