1981 Johnson 70. carb adjustment and synchronization

[9758JB]

Hi. 2 years ago i bought a Johnson 70 and after cleaning the carbs has been running very well for about a year. idles greats, runs great. Doing some reading i want to get the carbs synchronized to be sure none are running lean. i have a suspicion they are close, but i want to be sure

Standard procedure is to adjust mixture screw to fastest idle, then drop total idle and begin to synchronized . Well these do not have that mixture screw as far as any of my research goes. so do i just synchronize them without that step?

If not, what do i need to do?

also, where is the location for the synchronizers to screw in and what threads?

 

[jimmbo]

There is provision on the linkages connecting the carbs with each other for getting them synced to each other. At Idle, all the carbs are supposed to be fully closed. Once they are Synced to each other, then they need to be Synced with the TIming. That adjustment is what is commonly referred to as the 'Link and Sync'.Here the timing is advanced from idle to a specific Timing Spec. This is the point where the Carb is about to come off fully closed, if the timing is advanced any Further. The Specific Timing Spec varies from Engine Model to Engine Model.

You should get a Model Specific(Factory) Service Manual for you engine.

 

[9758JB]

Thank you. I'm working on getting a manual now