There would be no advantage to getting into the crankcase. With the spring and retainers out, a small burr on the stem- likely at the retainer area is what is holding you up. Spin the valve while holding the burr area in emery cloth or at the edge of a file. Take steps to catch any abrasives to keep them out of the engine. The valve is likely not bent, but inspect anyways. Good luck and happy new year.

could you have carbon on the valve stem, or maybe bent stem? I have only torn into one tecumseh, which was about 25 years ago but I dont remember any trouble getting the valves out. I think the keepers you are talking about are made in two pieces. The problem I had was getting the keepers back in. I tied the springs "compressed" and the cut the string when I had the keepers positioned. It really helps if you have proper tools.

Apples and oranges. The 2 engines have completely different valves and keepers. The sick engine has a notch at the end of the valve stem. The 1 piece keeper has an elongated hole . The donor uses a cup shaped perch and a pin that goes into a hole in the stem. I swapped the entire valve assembly,but it doesnt play. The engine is a H 70-130165A S/N 2174 R. I think the R means remanned. so that may be why the valve is different, I 'm guessing.

I found one in the 8 hoss junker, I had :)

It's alive! I used Slowpoke gardener's idea to use string to compress the spring and a C clamp and a piece of flat stock to hold the valve shut. It was a bit of fit and try but it went OK. I didnt even take the carb off. I wire brushed the head bolts and used them to clean the threads in the block. I oiled them and used a 1/2" cordless drill set on 10 to run the bolts in. Then I switched the drill to low and max torque. I finished of with a 1/4 turn of my 1/2" ratchet. I got a good squish on the head gasket and the engine starts and runs fine. Only expense was 75 cents for a 1/4" eye bolt for the chute control.