Re: walmart 2 stroke oil in 150 yamaha
 

Plugs? When was the last time you replaced the plugs . . . might be time to put in a fresh set and make sure that you gap them properly.

Re: walmart 2 stroke oil in 150 yamaha
 

You mentioned its the first time that you have used E10 treated gas. This stuff will mix with any water in your tank and if you had water in the tank (which most boat do) that could be your problem. Do you have a good water seperator on the boat and have you change it latley. From what I've heard allot of boaters will have to change their filter several times while the gas is mixing with the water and while its leaving the tank. I have one with a clear bowl which I had to drain several times and even replaced the filter twice. It now seems fine and I have seen no other problems.