1984 Mercury 18XD 18hp – not starting in neutral - need help setting primer/choke linkage after carb rebuild.
Looking for some help with an older Mercury 18XD 18hp outboard, serial 6456080.
I recently rebuilt the carburetor/replaced the float and had to disconnect the plastic linkage/primer mechanism and rod. I've got everything back together, but I'm not convinced the linkage is operating correctly. The two plastic toothed sections are meshed as far as I can get them. When I operate the choke/primer knob, there is basically no movement at the carb butterfly.
However, if I manually pull the metal rod connected to the plastic toothed mechanism toward me by only about 1–2 mm, the butterfly opens. So the butterfly and rod themselves move freely; the control just doesn't seem to be transferring enough movement to the rod. With the control pushed fully IN, the butterfly is closed. Pulling the control OUT doesn't noticeably change the butterfly position.
I've compared the new linkage position with photos I took before disassembly. On the original/broken plastic mechanism, the toothed sections appeared to mesh more deeply with essentially no gap. With the replacement part, I've got them engaged as far as they'll physically go but there is still a gap.
The engine currently won't start. It pulls over normally and the fuel bulb is primed. I've tried full and partial choke/primer with no luck. Before I start changing any adjustments, does anyone familiar with the 18XD primer/fast-idle linkage know:
-Is the butterfly supposed to move substantially when the primer/choke knob is pulled?
-Does this plastic toothed linkage look correctly indexed?
-Is there an adjustment for that ~1–2 mm of lost movement in the rod?
-Is there a specific setup/indexing procedure for the primer actuator/fast-idle linkage after removing the carb?
I don't want to start messing with the throttle/shift adjustment rods or stop screws without knowing what they're actually adjusting.
Thanks a lot!!