Hi Alton, welcome to Outdoorking.
The only 19.5 hp single cylinder Briggs I know of, is an Intek. If you post the Model, Type and Code numbers which will be on the engine top cover or cowl, we can identify it specifically and make use of the Briggs tech manual.
The Intek does have a compression release, and it is likely to be the cause of your problem. The starter motor does not have enough torque output to crank your engine through the compression stroke unless the decompressor is working. However the decompressor works by bumping the exhaust valve open momentarily in the middle of the compression stroke at cranking speed. Above cranking speed, it disengages and the engine has full compression. Unfortunately this means that the adjustment of the valve clearance is very critical: a slightly loose exhaust tappet will prevent it from working, and the result will be a burned out starter motor. This is why the Briggs operator's manual says you must adjust the valve clearance once every year: a small amount of wear in, for example, the rocker pivot, increases the clearance and leaves the decompressor not working. Furthermore after a substantial amount of use of the engine, the decompressor's operating mechanism on the camshaft wears down, and the valve clearance adjustment becomes more and more critical, until it stops working altogether, even at minimum specified valve clearance. When that happens, it is necessary to replace the camshaft since the decompressor cannot be replaced separately.
So, please do these things:
1. Post the Model, Type and Code numbers so we can make use of the tech manual in this matter.
2. Measure the valve clearances for both valves, and post them. If you are not clear on the procedure for this, I will explain it. Note that not all Inteks have the same specified valve clearances, so we need the Model, Type and Code to explain it.
3. If the clearances are not within specification, adjust them carefully to correct this. Once again, I'm happy to explain the process.
4. If the engine will still not crank over the compression stroke when the clearances are correct, we can further discuss the implications.
