77 Johnson

[DaleT]

I have a minor problem, model # 35E77, 1977 Johnson 35hp electric start. Motor starts but occasionally has what I would call a stutter to it, in addition when this happens it has a dark grey or black exhaust. This only occurs when it "stutters." I am currently cleaning and rebuilding the carb, at the suggestion of a boating friend, was thinking of cleaning and/or replacing the leaf plates as well. I bought the boat and motor used and was told it ran fine until it was taken out for the first time last summer, then it stalled in reverse and was pulled out of the water and never retried. The couple I bought it from had it winterized every October. Any tips or suggestions as to wether or not i am pursuing the correct course would be greatly appreciated. I have never had it on the water only in a tank. Dale

 

[G DANE]

Re: 77 Johnson

Hi <br />I think you are heading the right way. Black or dark grey smoke = far to rich air/gas mixture. Sounds like carb flooding some. Try to clean the little rubber tip on needle valve with fresh gas. Also check floater is parallel to carb body when turned upside down. Good luck.

 

[JB]

Re: 77 Johnson

Howdy, Dale.<br /><br />I agree with G DANE. The "studdering" is what we used to call "four cycling". It is the result of a too rich mixture.<br /><br />Red sky at night. . .<br />JB

 

[petryshyn]

Re: 77 Johnson

Did you try adjusting the idle mixture before pulling the carb down?<br />don't rule out ignition and compression either! Poor ignition and/or low compression both lead to rich exhaust....

 

[DaleT]

Re: 77 Johnson

Thanks Folks your help is most appreciated<br />Dale

 

[DaleT]

Re: 77 Johnson

I did try adjusting the idle to no avail. I happened to find another post on this forum about a similiar problem, which is why I asked, and in that post ignition timing was mentioned. After I get the carb. back on I will definitely have to take a look through the ignition system, as well as the compression. Dale

 

[petryshyn]

Re: 77 Johnson

wouldn't hurt to do a decarb and rule out detonation....she could be carboned up badly<br />This would be good to do on any motor bought used.....

 

[DaleT]

Re: 77 Johnson

Thanks Schematic that thought never entered my head, now that you mention it though it makes perfect sense. Once again I thank all of you, you're help has been thus far very benificial. Dale

 

[DaleT]

Re: 77 Johnson

Well here's the update. First and foremost, thank all that have assisted me through this project. I finally got the boat on the water today and it ran ok. Obviously needs some fine tuning, but that will get done now that I have the time to go out. Seemed to be lacking in power so next step compression and new spark plugs. I also have to replace the prop, some nice chunks out of it. In any event I am now on the water and able to cheaply fish, if that is possible. Once again many thanks to all of you.

 

[fireman 757]

Re: 77 Johnson

you might have your ignition coils checked. They could be cracked and arcing to your block. I have found a lot of times this will screw up your idle and top end.

 

[DaleT]

Re: 77 Johnson

Thanks Fireman, I will add that to the checklist. I'm not so sure I like boats anymore. <br /><br />Ah who am I kidding this stuff is great.