I purchased a 1975 Mercury 7.5 2-stroke (serial # 136279) a while back with a folding boat (12'Porta-bote). It looks like a pretty clean engine and bought from a trusted friend. 1st trip out I was impressed it got 2 of us and fishing gear on a plane. We were idling (cant remember if it was in gear) and the motor died. I almost ripped my arm off trying to restart it. The pull cord wouldn't budge. Had to get towed in. The shift lever felt like it was jammed (hindsight this could have just been difficulty shifting while not running). I ended up leaving it for another day, we moved and now restarting this project.
I think I accidentally gorilla armed the shift lever past reverse. It is now stuck in a 90 deg position to neutral facing forward (toward the front/travel direction of the motor in fwd gear). Question #1: How do I get this reset properly? I think the sector gears are out of alignment and are having a hard time meshing together.
It looks like I could take the carb off and start disassembling things at the shift shaft sector gear and maybe pull the shift lever assembly to rotate the sector gears to fit, but Im not sure how to line all of that up correctly (need to find a shop manual). Once I get that complete, I can position the lower in the correct alignment and get the lower back on to check shifting/operation.
In the lower unit, after some reading online threads I have tried rotating the shift shaft (carefully) with vice grips and seeing which way the prop spins when rotating drive shaft clockwise. When I have the blind spline of the lower shift shaft facing to the rear (back of motor/toward prop, opposite direction of travel when in forward gear) it feel like the lower unit is in forward gear, but there is some slop in the shaft and I can rotate it slightly counter clockwise fairly easily until a position that feels like neutral but there is some clinking going on when rotating shaft. A full 90 deg CCW turn with some fiddling will lock into what feels like reverse (the blind spline facing to the right went looking forward from prop to front the of gearcase/travel direction). Is this proper shifting? It's just a 90 degree motion and roughly 45 should be neutral?
Can I run/start this motor with the lower off so I can get it running again? (with a flush plug or something - looks like a flush screw on lower left side of cowl).
Sorry it's so long, I wanted to be as detailed as possible. I tried to upload pics but maybe too new. Thanks for any assistance,
I think I accidentally gorilla armed the shift lever past reverse. It is now stuck in a 90 deg position to neutral facing forward (toward the front/travel direction of the motor in fwd gear). Question #1: How do I get this reset properly? I think the sector gears are out of alignment and are having a hard time meshing together.
It looks like I could take the carb off and start disassembling things at the shift shaft sector gear and maybe pull the shift lever assembly to rotate the sector gears to fit, but Im not sure how to line all of that up correctly (need to find a shop manual). Once I get that complete, I can position the lower in the correct alignment and get the lower back on to check shifting/operation.
In the lower unit, after some reading online threads I have tried rotating the shift shaft (carefully) with vice grips and seeing which way the prop spins when rotating drive shaft clockwise. When I have the blind spline of the lower shift shaft facing to the rear (back of motor/toward prop, opposite direction of travel when in forward gear) it feel like the lower unit is in forward gear, but there is some slop in the shaft and I can rotate it slightly counter clockwise fairly easily until a position that feels like neutral but there is some clinking going on when rotating shaft. A full 90 deg CCW turn with some fiddling will lock into what feels like reverse (the blind spline facing to the right went looking forward from prop to front the of gearcase/travel direction). Is this proper shifting? It's just a 90 degree motion and roughly 45 should be neutral?
Can I run/start this motor with the lower off so I can get it running again? (with a flush plug or something - looks like a flush screw on lower left side of cowl).
Sorry it's so long, I wanted to be as detailed as possible. I tried to upload pics but maybe too new. Thanks for any assistance,