I am new to this forum and have a neighbor who had a Rider sitting in his garage, I inquired as to his willingness to sell and was told it hadn't been started in nearly seven years. The mower is a 1977. I can not find a manual for the engine Model #237707 Type 0235-01. Here's the story, rolled it across the driveway added gas as there was none. Engine seemed to be frozen pulled on starter rope a few times it loosened up ran maybe three seconds blowing smoke and oil and surprising to me old gas. Checked crankcase smelled of gasoline so I drained and added new oil.Started again ran maybe 10 seconds died and will not restart. Removed carburetor totally cleaner and replaced. Cleaned and replaced breather filter. Bought a new battery and hooked it up nothing than hooked directly to starter and it cranked but no turn over. Questions, could it be as simple as spark plug? Why won't the electric start work (Checked fuse)? Why gas in oil? Is this worthy of my time and money? What should compression be? Would cranking alone help blow out gunk from engine? Since it is a Briggs 14hp would it be easier to buy whole new carb vs dealing with the float? I am mechanically challenged but easily taught.