I have a B/S 15.5 engine 28N707. It has a hard time starting..almost like it is in hydro lock. If I take out the spark plug, it spins fast...so, maybe the compression release mechamism? If so, where is that located? I have a Sabre Lawn Tractor with a B/S 15.5 HP engine. Do I have to pull the engine to get to it? Is there a quick fix so that I can make it through the cutting season without pulling it? I read somewhere about leaving the spark plug lose till it starts. How can I tighten it with the wire on it? Thanks alot.

it may be your battery though sometimes, also some engines have higher compression anyway. yeah you have to pull the engine to work on the compression release, as for leaving the plug loose, you can do that, then with adjustable pliers with rubber covered handles tighten it up.

where is the release mech located?

around the cam, though its most likely the valves need to be adjusted >> read what bbnissan said http://www.hobbytalk.com/bbs1/showthread.php?t=94902

why grind the valves if the compression is too high...you lost me