85 Johnson 40hp - runs but no power

[ryans02]

I was running down the river yesterday at almost full throttle when I instantly lost all power. The motor runs smoothly but it is bogged down and doesn't have much power. I shut it down and check the plugs, they looked good. I visually checked everything else over and it looks good. The motor will start easily, idle great, but once you start to turn the throttle the motor is bogs down and doesn't have much power. Any ideas?

 

[HybridMX6]

Re: 85 Johnson 40hp - runs but no power

When's the last time the carbs were cleaned? Is it a tiller or a remote controls type outboard? It's hard to tell just yet, but could very well have got some crud in the carbs high speed jet, blocking it, which is why it will idle just fine but when you go to hit the throttle and the high speed jet kicks in, it's blocked, so you go no where.

 

[ryans02]

Re: 85 Johnson 40hp - runs but no power

This is a tiller . Not sure when the last time the carbs were cleaned, I have had the motor for 2 years and I haven't had them cleaned.

 

[steelespike]

Re: 85 Johnson 40hp - runs but no power

If it runs normally but is guttless it may be running on one cylinder.
Disconnect and carefully ground one plug wire at a time and see if it will run.
You also may be able to run it a minute and CAREFULLY feel the plugs.One may feel cooler than the other.