1978 Johnson 200 hp

[scole]

Whenever I run the engine for approximately 30 minutes it does not want to run at higher rpm's. It has a good flow of water coming out of the pee hole, and new plugs, and a new primer bulb. At lower throttle settings it sounds good,and when you give it a lot of throttle it sounds and runs rough and will die as soon as you put it in neutral. Any help will be appreciated

 

[R.Johnson]

Re: 1978 Johnson 200 hp

On this, I would certainly start with a compression test. Then, depending on what you find, do a running test on the fuel, and ignition. The fuel you can check by squeezing the primer bulb, or force feeding it through the carbs with a squeeze bottle of mixed fuel. On the ignition, ground out one plug at a time, and see if you can isolate the cylinder, or cylinders that are acting up. This is where a peak reading volt meter really pay's off.