1982 Johnson 50 missing and wont run above about 2000 RPM under Load

[bostonwhalermontauk1965]

Hi guys
I Thank you all in advance for any advice you can give me in this department. I finally got the old Whaler wet after it sat for over a decade. You can see the photos on my other threads. The problem is the engine seems to be missing and not running over about 2000 RPM in gear under a load.Its a 1982 Johnson 50. I put in a brand new tank with new line including a new filter and primer bulb. 2 New spark plugs,and fresh gas. It idles rough. I put a new internal engine harness in, and I want to eliminate the possibility of a bad stator or coil pack or packs. I dont know how to diagnose a bad one of either, but I am handy and a quick learner. I was an auto mechanic, but 2 cycle outboards are not yet my forte. (LOL) I am trying to correct the problem myself, but if I have to - I will drop it off at Marine Mechanic. Trying to avoid the second mortgage for repair and I dont want to leave my boat at their yard either if I can help it. If you look at pictures you will see why. How can I maybe use my voltmeter to diagnose the stator, transducer, and anything else that may be causing this? I really dont think it is my carbs, but I guess that cant be ruled out yet either entirely. Thank You again - Paul

 

[glengold]

Re: 1982 Johnson 50 missing and wont run above about 2000 RPM under Load

if it has sat for a decade you need to go through the carbs, I can go through mine in less than half an hour. If they look bad you will want to remove the core plugs and give them a long soaking. you need to take the main and idle jets out and make sure there isn't anything blocking the flow of fuel. Use a strand from copper wire to clean out the jets.

make sure there is a clip holding the float needle to the float arm. you may want to just purchase carb rebuild kits and then you have all new internals for your carbs. If the gaskets are black then the internals are all original. the rebuild kits come with brown gaskets.

If you find little bits of black rubber in the carbs it is from the inside of your fuel lines breaking down because of ethanol. You need to replace all fuel lines to "newer" alcohol (ethanol) resistant ones.

After you have gone through the carbs i would do a decarb procedure on the motor. Takes about an hour or two and costs less than 20 dollars. I did a decarb this weekend on an old 55 evinrude and picked up over 600 rpm. The motor was a little sluggish before but not as bad as yours. In my case it made a HUGE difference.

 

[bostonwhalermontauk1965]

Re: 1982 Johnson 50 missing and wont run above about 2000 RPM under Load

Thank You very much - I will check the carbs!!!

 

[Monte1961]

Re: 1982 Johnson 50 missing and wont run above about 2000 RPM under Load

Hi guys
I Thank you all in advance for any advice you can give me in this department. I finally got the old Whaler wet after it sat for over a decade. You can see the photos on my other threads. The problem is the engine seems to be missing and not running over about 2000 RPM in gear under a load.Its a 1982 Johnson 50. I put in a brand new tank with new line including a new filter and primer bulb. 2 New spark plugs,and fresh gas. It idles rough. I put a new internal engine harness in, and I want to eliminate the possibility of a bad stator or coil pack or packs. I dont know how to diagnose a bad one of either, but I am handy and a quick learner. I was an auto mechanic, but 2 cycle outboards are not yet my forte. (LOL) I am trying to correct the problem myself, but if I have to - I will drop it off at Marine Mechanic. Trying to avoid the second mortgage for repair and I dont want to leave my boat at their yard either if I can help it. If you look at pictures you will see why. How can I maybe use my voltmeter to diagnose the stator, transducer, and anything else that may be causing this? I really dont think it is my carbs, but I guess that cant be ruled out yet either entirely. Thank You again - Paul

I will concur with carb/s overhaul. Just for sh*ts and giggles, have you done a compression test? Have you checked for good hot spark? You say you are a auto mechanic, so with that in mind I am sure you would have, but just in case you haven,t. Post results.

 

[bostonwhalermontauk1965]

Re: 1982 Johnson 50 missing and wont run above about 2000 RPM under Load

Thank You for your help.... I plan on rebuilding the carbs. They have never been done. They are the originals. The problem however ended up being a dead upper cylinder ignition wise. I am leaning toward a dead coil or powerpack because so far I believe the stator checked out ok. My question to you is ...What is a decarb procedure exactly. Picking up 600 RPM sounds good... so how did you do yours if you dont mind? Thank you very much Glen. Paul