[metalstudman1]

Not hear to bust your chops- But as just one user of the GY6 I can say that they're great simple engines. Put out a ton of horsepower for such a small size and turn incredible rpm's without failure or overheating. I think the fact that you hear so much about them is that they're on LOTS of vehicals using them & being abused and NOT maintained by people that think it should just work without any working on it!!- and you can buy parts for these engines EVERYWHERE. I've never blown up one of them up or broke a part out of 5 that I wore out to the point of some smoking and still ran great. Do some more research and you'll understand my opinions.There's a reason you won't find others replacing the GY6 with a lawnmower style engine(3600-3800rpm's). The idea of switching to a Briggs is just down right funny- you're poor Spiderbox won't perform anywhere near that of the GY6- (rpm's & enclosed variator/clutch spells power in this case).You might get close if you installed a Briggs 15hp,then weight becomes an issue since the GY6 is only about 55lbs.

I'd try adjusting the valves to see if it starts better (before assuming it's an enrichment valve issue,doesn't cost anything to adjust valves)- very simple to do, remove valve cover bolts, rotate engine till one off the rockers/cam lobes are all the way up(loosen the nut on the rocker arm stud) and slide a .003 feeler gauge between the valve top and rocker arm with little resistance on both intake & exhaust,tighten nut down, then rotate to the other valve.They tend to get tight over time and this maintanance is needed everytime it get's hard to start.