1978 Johnson 35 Throttle Link & Sync Help

[shooter5636]

You guys have become my go-to resource for this motor. These questions may be a pain, but I learn something from this community every time I post a question.


So I need some help with the throttle linkage and if it is in sync or if I need to reset everything. I've tried following the service manual for it, but I learn and understand better by seeing, and it's pretty limited on picures. I've been having problems with the motor ever since I brought it home. It wouldn't idle for me. I ended up getting the idle adjustment worked out and the RPMs sitting nicely around 900 but the needle valve is currently adjusted out something like 4.5 turns..... The motor says the starting point is 1.5. The motor would have a mean lean sneeze if I tried to lean the mixture up at all. If I choked it out, the lean sneeze would go away. Are some of these motors just that thirsty? The motor accelerates as it should all the way to WOT.


Pictures of throttle linkage:

The throttle has to advance this far before the butterfly begins to open:

 

[shooter5636]

Video of lean sneeze/missfire before backing out the needle:

https://www.youtube.com/watch?v=17AReCfQoeA&feature=em-upload_owner

 

[RCO]

The link n sync doesn't have any bearing at idle, the carb butterfly is closed and the timing advance controls the engine speed up to the halfway or so point. 4.5 turns of the mixture screw seems excessive to me, have you taken the carb completely apart? I would suspect that something is either partially restricted in the carb, or there is an air leak from the intake/carb or crank seals.

 

[shooter5636]

The link n sync doesn't have any bearing at idle, the carb butterfly is closed and the timing advance controls the engine speed up to the halfway or so point. 4.5 turns of the mixture screw seems excessive to me, have you taken the carb completely apart? I would suspect that something is either partially restricted in the carb, or there is an air leak from the intake/carb or crank seals.

The carb is supposedly a fresh rebuild per the seller. The gaskets look new, but I, myself, haven't opened the carb up and looked at it. I supposed I should eliminate the easy stuff first.

Whats the process for testing for a crank seal leak?

 

[G DANE]

I think the solution lies in the trottle linckage adjustment. Adjust the linckage so that the carb butterfly does not open at all, before the 2 small marks on top of the cam om the stator plate shown in your photo is at the roller. This is important, the motor will leansneeze if the butterfly opens before the ignition is advanced to the point where the roller is between the marks.