150 johnson power loss

I was away for 3 weeks and when I came back the engine seemed to skip loose power at 3/4 speed. It’s not a constant problem and the Warning horn and light (check Engine) has only gone on once, the first time it happened. I changed my water fuel separator filter and that problem seemed to have gone away. <br /><br />Yesterday I decided to open the engine up some. I usually run at 4,000 – 4,200 RPM. I went to 4,800 no problem then I pushed the engine wide open within seconds the engine stopped as if I ran a ground, but I didn’t. No power shut down!<br /><br />I’m not sure if it stalled or I shut it off, but it didn’t start when I turned the key right away. I paused then it started and I finished out my day without any problems going as high as 4,400 RPM’s <br /><br />Any thoughts?

Re: 150 johnson power loss

Just a shot in the dark. But I had a customer describe the same actions. Bottom line here was you need to pull the plugs and check them for signs of water getting to one or more cylinders.The plugs will tell you alot of info. In his case he trouble shooted it while running and sized one cyl that was from a headgasket leaking into #6 cyl he never got an overheat alarm as the motor remained under that over temp setting! Check those plugs to see if there ares signs of water.