Johnson 40hp outboard issue..... please help!

[Justplainmitch]

Hey guys, I am having an issue with my 1990 40hp 2-cycle Johnson, and of course I am supposed to leaving on a fishing trip in Canada on Saturday morning. My motor will idle fine, and even rev in neutral. The problem comes when it is put in gear and given throttle. The motor will bog down severely. Can only get the boat up to 5-10 mph. Any ideas? I recently had the impeller/water pump replaced, as well as the carbs cleaned. Any help would be great! Thanks

 

[racerone]

Standard procedure as follows.-----Do a compression test first.----The see if spark will jump a gap of 7/16" or more on both Leads.----Sounds to me that your motor is running on one cylinder.---And yes running on one cylinder it will rev up fine in neutral.----Could be you have water in the fuel or a bad sparkplug too.----You have to do the checks and report what you find.

 

[Justplainmitch]

Standard procedure as follows.-----Do a compression test first.----The see if spark will jump a gap of 7/16" or more on both Leads.----Sounds to me that your motor is running on one cylinder.---And yes running on one cylinder it will rev up fine in neutral.----Could be you have water in the fuel or a bad sparkplug too.----You have to do the checks and report what you find.

Both cylinders read at 80psi. Good spark on both plugs. Thanks for the help.

 

[kimcrwbr1]

Do a cylinder drop test while idling pull a plug wire and put it back on. The engine should respond the same onboth cylinders.

 

[Justplainmitch]

Problem solved! It was a bad seal on the carb. Got it fixed and out running like a champ. Thanks for the help!