I have a 1990 40hp evinrude that I unhooked the VRO to get rid of the ringing and mix gas 50:1 ratio. The engine starts right up when I put it in the water but after running for a few minutes to a few hours I go to start it up and it won't start. I was running the boat down the river at a low speed and the engine just quit. After about 15 minutes or more and trying to continually trying to start the engine it started up and ran like nothing was wrong. The primer bulb was nice and hard when I tried to restart it so I know gas is getting to the engine. I replaced the spark plugs last summer and all fluids are full and fresh. Thanks for the help!