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76 Johnson 70HP running rich!

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kevin78121

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I have a 76 Johnson 70hp that has run rich ever since i bought it 4 years ago. I found out that the carburetors ,on the recently overhauled motor, have been modified per Johnson service bulletin 1144. Just wondering if y'all think that this modification has been my problem from the get go. The carbs have been cleaned and a kit put in each one. At the same time replaced low and high speed jets. My main complaint is that I have to feather the throttle to get to plane. If I go to WOT it just loads up and dies. The Motor has 100psi on each cylinder. Any help will be extremely appreciated.
 
I have included some pics about the service bulletin. All the carbs have been modified this way, thanks



76_70HP CARB BULLETIN3.jpg76_70HP CARB BULLETIN2.jpg76_70HP CARB BULLETIN1.jpg
 
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It seems to me that it is not loading up ----It is still running lean.----------You have spark on each cylinder that jumps a gap of 7/16" or more ???
 
Thanks for the help. I did check the spark gap and they all will span 7/16 with a blue spark. The plugs are always a dark brown and very wet in all cylinders. I replaced all the Reed valves and fuel pump. The coil packs are new also.
 
Thermostat in place and working ???------------------If throttle opens too soon the motor will die.-------------Check synchronization between spark advance and throttle.---------Do you know where the motor was rebuilt ???
 
Sorry for the late response but work has been very busy. The thermostat was replaced when my dad and I overhauled the motor about 3 months ago. Is the spark advance and throttle controlled by the same cable? I do know that the throttle cable hangs or its not as smooth as it should be but just ordered replacements. I'm also cleaning the carbs again. Thanks again.
 
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