Need Evinrude expert, motor issues...

[abesz]

The motor is a 1985 Evinrude 150 (E150tlcos), having acouple issues. One, motor cuts off while running in water at full board. I can plane out and run the boat at full throttle at roughly five minutes, then the motor cuts off. Once I start it again, it will run up to about 90 percent of full throttle. Second, the motor seems to have a slight miss-fire to it. Here recently what I've changed and need some new advice on what else could be the issue. Thanks...

-new plugs
-new gas, and oil
-new sparkwires
-new gas filter
-checked carbs, clean (were redone about five years ago)

 

[daselbee]

Re: Need Evinrude expert, motor issues...

Pump the primer bulb as you run it. By doing this, you are acting as a manual fuel pump. If it quits cutting out, bad fuel pump.

I have a 1985 150, parting it out. Will make a great deal on parts for you.
PM me if interested.

 

[abesz]

Re: Need Evinrude expert, motor issues...

Will try, otherwise what else could be the problem? How much would you want for your fuel pump?

 

[GatorMike]

Re: Need Evinrude expert, motor issues...

Not a mechanic but something I have learned over the years with my own outboards is to keep one of the old plastic 6 gallon external tanks in the garage for occations like you have right here. Run it off an external tank and if you have the same problem at least you have isolated it to the motor itself, you know you have no fuel tank or delivery problem.

I came back to edit this with a quick story. A couple of years ago I was Vacationing at Marco Island. I had been having fuel troubles all week and couldn't figure out why after running about 300 yds at WOT my boat would fall flat on it's face. I took the 6 gallon tank out of my sons skiff and plugged it into my motor and it ran beautiful. I ran the rest of the week off of an external tank. Later in the week I ran into another boater at the condo next to ours who happened to have the same model boat and motor I do and he was having the same problem. I put my external tank in his boat and it cured his problem too.

Once I got the boat home and had the chance to investigate it turned out there was a fuel filter hidden up under a corner of the bilge that I had never seen. The filter had never been changed and was clogged.

 

[abesz]

Re: Need Evinrude expert, motor issues...

Thanks for the advice, but I've already took a sneak peek for that when I replaced the fuel line. Thanks though...

 

[emdsapmgr]

Re: Need Evinrude expert, motor issues...

Could be an ignition problem. Weak ignition components tend to fail when the engine warms up to normal running temps, usually a few minutes after startup. I'd check the spark on the engine when it starts to act up. Take an inductive timing light with you. When it starts to act up, put the timing light on each plug wire and check the flashes from the gun. You will be able to see misfires or nofires easily. Make sure the engine is under load when testing (in gear-idling.) If you don't see any evidence of ignition problems, go back to the fuel system diagnosis.