74 johnson 9.9 rough idle

indystevie

Cadet
Joined
Jul 30, 2007
Messages
12
new plugs, gaskets,coils, wires,etc... carb is totally clear. compression is good. wot- okay, idle seems to be weak... timing, points, condenser etc, good.... any suggestions?????
 

indystevie

Cadet
Joined
Jul 30, 2007
Messages
12
Re: 74 johnson 9.9 rough idle

I know the carb is set up right, for sure. I did notice today that when the t-stat opens, it really gets rough. I wonder if the head gasket is leaking through? Another real strange thing, when I put the hood on, I only get 1/2 the rpms???? I checked for venting...looks good. I wonder if the coil(s) or wires may be arcing.......
 

bgbass.1

Chief Petty Officer
Joined
Aug 1, 2007
Messages
558
Re: 74 johnson 9.9 rough idle

if your getting exaust under cover it wont run right
 

indystevie

Cadet
Joined
Jul 30, 2007
Messages
12
Re: 74 johnson 9.9 rough idle

possibly running it in a barrel may have something to do with exhaust ingestion????
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 74 johnson 9.9 rough idle

if your getting exaust under cover it wont run right. possibly running it in a barrel may have something to do with exhaust ingestion? both are good answers, and your theory ain't bad. check your compression, again. also make sure both are firing after it warms up.
 
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