I rebuilt my top end all new gasketz and plug and oil. It just cranks but wont turn over. Carbs fine the timing is fine and still nothing. I need help fast. Got to plow with it. Thanks in advance. Oh btw is an 2007 honda foreman 500 es

 

Three main things
1. Check for fuel
Get some starting fluid and spray it down the carb while cranking. If it fires up and runs for a second then fuel is the issue.

2. Check for a spark
Pull the plug put in wire and ground plug to block and crank, see if you are getting a spark. Make sure the plug has a gap and is not fouled.

3. Check for compression
Get a compression tester, if you rebuilt the head this is likely the problem, valves might not be opening and closing properly.