1989 suzuki 75 hp power loss

[clydey]

Recently was asked to take a look at this outboard because of power lost while taking a cruise. Boat and motor was running fast and strong and all of a sudden bogged down to 10 mph and won't recover.Push it to full throttle and 10 to 15 mph and that's it.Any ideas? Carbs were taken off and cleaned thinking it was a fuel issue but no change.No misfires or clunking in the motor either.

 

[Toddboat]

Re: 1989 suzuki 75 hp power loss

Remove the prop, make sure there is nothing wrapped around the prop shaft that could be slowing it down.
If that checks out, then perhaps there is an air leak somewhere which is making the mixture too lean.
Or perhaps an electrical arc (leak). I had similar symptoms once and it turned out to be an electrical arc.
I never would have found it myself.
Just some ideas.

 

[ohabu]

Re: 1989 suzuki 75 hp power loss

I've found that engine running fine and then suddenly losing power/not reaching correct rpm is usually the fault of a bad spark plug. Could also be a bad coil/electrical, but if its not consistent it is usually a spark plug problem.

 

[deejaycee_2000]

Re: 1989 suzuki 75 hp power loss

Did it limit the RPM's?

 

[99yam40]

Re: 1989 suzuki 75 hp power loss

check to see if alarm system is functioning properly. Might be in alarm state but Buzzer is not going off
Check compression, spark, and timing to make sure everything is still good if it will not get up in RPMs any more

If all is good then look at fuel system