Farmall Cub

So I should lap them? How do I check/adjust the clearance?

Since you have the head off the engine, remove the valve tappet cover located on the left side of the engine. Check for valve tappet clearance. There is a section in the service manual and perhaps the operator's manual on adjusting valve tappet clearance.

Then, as you rotate the engine by hand to lift one valve at a time, inspect each valve face and seat for seating and damage.

Thanks; I found it in the General Maintenance Manual.

So I tore down the cub engine, removed and cleaned and lapped all the valves and oiled the guides, re installed, adjusted the lash... put it all back together.... cranked and cranked and cranked.... nothing...

Today I decided to replace the carb with one off of my running tractor... Then instead of cranking the engine over by hand I pulled it with our JD and after a few yards she began to smoke and roared to life. I had no oil pressure showing up on the gauge so I shut it down and pulled the cover off of the oil filter housing and it was full so the pump is working.... just a bad gauge.

After the pull start she began firing up with the crank handle and she is purring like a kitten. Tomorrow I am mounting the cultivators... After at least three years setting a nother one springs back to life.

I have never understood why Cubs will start when pull started but will be difficult as the dickens no matter what you do to start them. Ellie did that to me after sitting for 6 months and Granny did the same thing after sitting idle for a couple years. Not sure why ... is it because of the higher rpms when pull starting

my first guess was a shorted rotor button shorting to shaft. Found this on occasion.

Two up and running ,new seals in finals ,new brakes starters and generators reworked. Picked one today to have something to piddle with. Got to get greasy . Otis almost 70 years pulling wrenches and still loving it . When nothing works and later
you drive it out gives you a big thrill.