Duden89

The shut off issue was just a matter of me not having a chance to look at it. The wires just fell off the ignition key and the shut off works now (but the position of the key doesnt matter when it comes to startin and stoppin, not a big deal though). The pinging is what I was worried about. I thought it might have been the bad spark plugs but even with new plugs it pings. It will run ok for about 30 seconds before it bogs down and shuts off. I was thinking it was pre-ignition but I wasn't for sure. There is an exhaust leak on the magneto side that smokes and blows some oil on the exhaust pretty good. I checked the spark plugs and the side with the leak was a lighter color, a light tan color as compared to a medium brown on the other side. Whats the probable cause of preignition? Carbon build ups on the pistons? Would preignition cause the motor to shut down like that?
Forgot to mention that the coolant reservoir tank isnt hooked up to the cooling system. Its got a couple of dead bugs in the tank and there isnt a hose connecting it to the system. Not sure how its supposed to work but It has coolant and never had a high temp light come on. Also the carbs like to spit a little bit of fuel back through the intake side of them.