35 johnson runs bad with cover on

dwg

Cadet
Joined
Apr 12, 2010
Messages
6
I recentlt got a 77 model 35 hp johnson.with the cover off I got it running ok,but it smoked excessively,and I hard time finding the sweet spot between idle and power(carb adjusting).When I put the cover on,it went south,and fast.I just dont see where it can pull enough air to run.
 

rjezuit

Chief Petty Officer
Joined
Sep 24, 2007
Messages
418
Re: 35 johnson runs bad with cover on

In a barrel or on a moving boat?
 

wilde1j

Vice Admiral
Joined
Apr 15, 2002
Messages
5,964
Re: 35 johnson runs bad with cover on

Likely exhaust leaking into motor cover space from a gasket leak (adapter, exhaust cover, etc.).
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: 35 johnson runs bad with cover on

There is no "power adjustment" on the carburetor. The knob is for idle mixture only. Set it for best idle and the high speed will take care of itself. That is, if everything else is as it should be.

The previous remark is right on--are you running it in a barrel? Don't expect it to run in there with the hood on, because it won't. Rest assured, it will get enough air if running on a boat on the lake. The engineers though of that. And it won't smoke so bad either.
 

dwg

Cadet
Joined
Apr 12, 2010
Messages
6
Re: 35 johnson runs bad with cover on

It was in a barrel,and it sat for a while i went ahead and ordered a carb kit and exhaust gasket.Will I need anything else for the exhaust job?Parts wise.
 

restornator

Petty Officer 1st Class
Joined
Aug 15, 2009
Messages
361
Re: 35 johnson runs bad with cover on

a lot of members recommend using a fan to blow away the exhaust while running in a barrel
 

dwg

Cadet
Joined
Apr 12, 2010
Messages
6
Re: 35 johnson runs bad with cover on

when i rebuild this carb is there anything i should do different or know about,vesus a car or brigs,ive built alot of carbs just not a boat.
 

jeff_smith_0423

Chief Petty Officer
Joined
Dec 5, 2007
Messages
492
Re: 35 johnson runs bad with cover on

Get a service manual for your exact model before attempting the carb rebuilt unless you've rebuilt 2 stroke carbs before. They're not hard but they're not like an automotive carb.
 
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