I have a 1989 Johnson 150hp v-6 running premix. How low should the compression be before I decide that the motor is just too worn out to keep putting money into it? A mechanic told me my boat has already reached this point. My compression for all cylinders are from mid to high 70's with none varying by 10% or more. I've recently decarbed, and I crank the motor fast when testing by removing the plugs and using a large battery. What do you think? Should I scrap this motor? What needs to be done next on this motor (I think) is to pull the six carbs and clean the jets. I don't know if I have the skills to do this and the mechanic says the engine isn't worth enough for me to pay him to do this.
