40hp 1989 johnson running poorly

[bikegod66]

here are the symptoms : idles poorly,motor stumbles with any acceleration for a moment then clears up,running wide open if you bump the choke it will gain about 300 rpms. when idling if you hit the choke it will run smoother as well. i just bought the boat and have replaced the fuel and the plugs.

 

[Joe Reeves]

Re: 40hp 1989 johnson running poorly

Check the compression which should be 100+ psi and even on both cylinders. What do you have?

With the s/plugs removed, the spark should jump a 7/16" gap with a strong blue lightning like flame... a real SNAP. Does it?

Spark plugs should be Champion QL77JC4 plugs, gapped at .040.

Remove, clean, and rebuild the carburetors. Improved performance when hitting the choke as you state indicates that the carburetors are somewhat fouled, clogged, gummed.

 

[bikegod66]

Re: 40hp 1989 johnson running poorly

thanks for the advice, anyone wanna recommend a boat mechanic in georgia ?

 

[fireman57]

Re: 40hp 1989 johnson running poorly

What Joe suggested are very easy to do yourself. If you want to pay the shop 60+ dollars an hour that is fine. I'm guessing that you came here looking for how to fix your engine and it seems like you are giving up already. Compression tester at my "local cheap auto parts place" is about ten dollars. You can spend another ten getting a spark tester. One more dollar will get you a cheap feeler gauge to set the gap on the spark plugs. You can go to your local library and check out or at least look at a Hayne's or Chilton manual that will lead you step by step through the carb rebuild. The kit from you dealer will only be about twenty bucks. It is not hard if you have ever done anything mechanical before. You are talking about spending at the most fifty bucks on items that you will use time and time again if you are going to keep an outboard. Don't be scared to try and fix this simple problem yourself. If it is already not working right I don't think you can make it worse. There are plenty of threads on rebuilding a carb. A carb rebuild is basically just replacing the parts in the kit with the parts on your carb. You will want to soak it overnight in a carb cleaner and blow out the small tubes in it with compressed air. You don't even need an air compressor just buy a can of it at your local office /computer supply store. Just do a search on this site and you should have no trouble at all. I see that this is your second post here but I am going to say this anyway. Welcome to iboats!

 

[bikegod66]

Re: 40hp 1989 johnson running poorly

thanks for the info guys, i have already taken the boat to the doctor. they said the carbs looked terrible. i am a pretty capable mechanic it is just more a matter of time for me.

i will give a report on how good of a job these guys do for me. seems good boat mechanics in georgia are hard to come by.

 

[Joe Reeves]

Re: 40hp 1989 johnson running poorly

You better hope that your mechanic in Georgia isn't reading this. (grin)

 

[fireman57]

Re: 40hp 1989 johnson running poorly

When you get your bill I bet you do it yourself next time. These things are pretty simple to work on you just have to have a little patience and the time to do it. Make sure that you stick around the forum even after you get your boat back and read some of the threads. It's amazing what these guys know and will share for free.

 

[bikegod66]

Re: 40hp 1989 johnson running poorly

boat ran perfect all day today and i caught alot of fish to boot.

thanks d&p marine for the fast and great work, worth every penny.

 

[fireman57]

Re: 40hp 1989 johnson running poorly

Don't leave us in suspense. What did they do?