How can I get my 11hp motor to start under load?

I have a home made log splitter that I recently got a new motor for. It is a 11hp chinese motor and I've read nothing but good things about it in reviews. The brand name is greyhound. Any way I connected it to the hydro pump ( a pto driven pump originally ) and cant get it to start under load. When I disconnect it the motor fires right up. I think im going to go with a belt drive with a fly wheel tensioner but was looking for some other suggestions. Anything will help.