I have a 2 year old snapper with a 6.75 hp briggs ohv that won't start when it's hot even with starting fluid. It has been getting harder to start when cold, but it will start. I checked compression (90 psi) both hot & cold, swapped coil & carb with another mower. I also pulled the valve cover when hot & there is clearance between rockers & valves (didn't have the spec. to see if it was correct). Any suggestions would be greatly appreciated.

sounds like the valves aren't in spec..... course i don't know the specs for it myself

I checked the valve clearance, it was arround .010 on both, I reset to .005 & it starts much better. I wouldn't think that .005 diff would matter, apparently it does. When hot I still sometimes have to use the primer, but it starts. It has electric start, wont restart hot with elec. starter. I think the battery is bad, i'm going to replace it. Thanks for the help! :)

That small amount will make a huge difference when it comes to valves. However, you need to set you exhaust side valve to about 0.007"...it should have a slightly larger clearance than the intake side.