Re: lower shift rod adjustment
The lower shift rod is not used for adjustment. As far as I know, it usually should be threaded in all the way and only backed out enough to match the holes in the coupler. The only reason for backing it out would be if the coupler contacts the leg casting in forward gear position. Perhaps the 150 and newer 4 cylinder engines have a longer or thicker casting that needs 4 threads--I have never done a 150. I always keep the lower rod all the way in and adjust throw up under the carb. I do have one 120 that almost contacts the casting with the coupler in forward and if it were to have contacted it, then I would unscrew a couple of turns to be certain that I was getting full throw to forward gear.
At any rate, it is easy to unscrew it with everything assembled so I would try all the way in. Then if I needed more clearance, I would go a couple of turns out.
On a 35. 45. 55 engine, it should be screwed in all the way and backed out only to the appropriate angle
