1975 prealpha engine alignment

[boatbrothas]

My cousin and I are working on a 1975 140hp/181c.i. (serial number in the 3.7million range) with the round coupler. Upon reassembly we noted the heli-washers and the nylon spacers were missing and was causing major trouble aligning the engine coupler with the gimbal bearing upon reassembly. After, placing the heli-washers and nylon spacers between the rear motor mounts the engine is now MUCH closer to being aligned (as far as we can ascertain.) The local marina was nice enough to loan us both of their alignment tools (part no:805475), but they are slightly too big and will not go into the coupler. We made a general alignment tool with tape and a pole that fits the coupler and the gimbal bearing very closely (obviously not a machine fit), which seats against the back side of the coupler without ANY resistance whatsoever.

The marina mechanics stated they have never had a problem with their alignment tool working for them, but does not fit into the coupler. We were going to take the boat to them for alignment, but they don't have the correct tool. So, I guess we are on our own here....

The out drive is currently about one-inch from being seated and the threads have not came through yet so we can put the six nuts on.

Is the gimbal bearing on this unit supposed to slide slightly left and right?

Does anyone have any ideas

I have dug around the board and gathered some excellent info from mercstuff.com and other postings.


We cant see paying nearly 100 for an alignment tool that will NEVER get used again.

 

[Haut Medoc]

Re: 1975 prealpha engine alignment

The Merc alignment tool is one size fits all....
You are out of alignment, the Merc bar should fit.....
If it does not either you are out of alignment or the coupler splines are so pointy that the tool will not fit.....
There is no side to side play in the gimbal bearing, per se.....
Try feeling on the inside where the input shaft goes into the coupler while the other guy tries to push it in.....
You may need to turn the prop ccw to get the splines to engage.....​