Mercury Mark 30 shifting adjustment

[Johnson RD]

My 1958 Mark 30 tiller runs nicely from idle to full throttle.   I have tried to adjust the throttle and shift lock drum to get it set near 1,800 rpm for proper shifting (per service manual) without success.  It’s nearly twice that rpm and the linkage from the cross shaft to the shaft that controls the magneto won’t allow enough movement to set it correctly.  Any thoughts to what I’m missing? I removed the magneto for service and noted where all the linkage connects when I installed it. It will shift into forward from neutral when the shift lock drum is not contacting the shift lever.

[Johnson RD]

Serial # 1166400

Magneto Fairbanks Morse Type FM    XV4B70F

Small taper flywheel

From what I’ve researched it should be a 1958 model.  However, I have discovered that 1958 motors should have a large taper flywheel with a Kiekhaefer Magneto.  Also read that they often substituted parts from different years when necessary.  It was converted to tiller steer at some point.  Previous owner had no idea of its history.  It was in a barn on property he purchased.

[Author]

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