Is it a Mercury 4 stroke. My neighbor has a 40 Mercury 4 stroke and it would crank and run down the lake just fine, but when you tried to crank it again and it would not crank and if it did and you gave it any gas it would go dead. There is what looks like a small tank on the left side of the motor but it has a pump in it. It would get hot and if I splashed water on it for a few minutes and cool it off, it would crank and run fine again. I know, it sounds stupid and it is what I thought when the owner, he's 85,first told me to do it,but it worked for 20-30 times until we fixed it. We replaced the pump inside and problem fixed. After about 10 times on the lake, I told him I would buy the pump if that would fix it.