Hi, I am new to the forum and have a problem with my 16 HP OHV B&S. When I try to start it up it act as if my battery is dead, but it is not it will not spin the motor over. I can take the spark plug out and it will spin freely but as soon as I put it back in acts as if the battery is dead and will not turn over. I have replaced my starter as well as solenoid and it does not help. I have even tried to jump it off and to no avail. I will let it sit and then out of the blue it will turn over and run like a sewing machine. Don't shut it off, because you will go thru the whole ordeal again. I was wondering if maybe my valves need adjustment and not allowing the exhaust valve to open so too much compression. I was thinking also of timing but once it starts it runs great, this is what throws me :confused:

The valves do need adjusting.
http://faqs.custhelp.com/cgi-bin/faqs.cfg/php/enduser/std_adp.php?p_faqid=3441&p_created=1101860144

sounds like the valves like bug man said . also if the carburator leaks fuel in the cyls it can also make it hard to turn past top dead center . does it kinda whirl then come to a dead stop or does it crank slow the whole time