Have a 18.5 hp twin and starts up good. Seems to run real good. But after 30-40 minutes if mowing it dies and won't restart til it's good and cooled down. I have changed the coil and plugs. All good gas and nothing looks dirty don't no alot about carb adjustment or anything. Any help is appreciated. Pretty handy on diy just need to know what I'm looking for and tips on making sure all adjustments are correct