97, 75hp,3 cylinder Merc - Questions about the shift slide and remote control

[KEYCHS1720]

Motor: 97, 75hp,2st, 3 cyl, Mercury Serial 0D283222.
Remote Control: Mercury Remote Control 88688A26 - good condition
16' Shift Cable: Removed from boat, I believe to be original, smooth, appears to be in great shape.

After performing an oil change, impeller change and bearing carrier seals I have found myself in a difficult decision with my lower unit and its shifting abilities. I'm able to locate F,N,R while spinning the shift shaft on the LU CCW. However, despite having the LU and remote control in neutral when I reassemble the motor, I'm unable to shift into forward from neutral at the remote control. I have adjusted the shift cable in everyway, I believe my problem lies with the timing/location of the shift-slide in relation to the shift lever/upper shift shaft and how it couples with the lower unit's shift shaft. I believe this is to be this issue because the shift lever disconnected from the shift block due to a loose bolt during this ongoing process. I've found a picture in the service manual , attached and link below.

Can anyone explain the significance of having the shift block pulled all the way to the front a 1/8 (3.2mm) past the front of the shift rail? I'll also take any advice anyone else has to offer!

Gearcase Installation - Mercury 75 Service Manual [Page 486]

Mercury 75 Manual Online: Gearcase Installation. Disconnect (and isolate) spark plug leads from spark plugs before installing gear housing onto drive shaft housing. Failure to follow this warn- ing could result in accidental engine starting and possible injury. a c 1. Position outboard...

www.manualslib.com

 

[Texasmark]

I have the service manual for those engines from '94 through 2005ish and have and had a 90 and 115. I do not recognize your picture and there is nothing in there that looks like that.
My engine shift mechanism is a sliding (fore-aft) linkage arm, with a vertical pin (screw) with locking nut that attaches to a hole in the end of the plastic tipped, center cable conductor from the remote control.

The cable's outer, threaded, brass tube contains a barrel shaped device that can be positioned up and down the tube and is secured in the engine in a plastic slot (with plastic flip cover) about 2" back from the cable entrance to the engine. The barrel is positioned such that you have a slight "pre-load on the cable....meaning you rotate the barrel such that the shifter is comfortable in it's slot....wiggle back and forth, and once the barrel is positioned such that the hole in the end of the plastic shifter is directly over the threaded "pin" for a given gear, you pull the cable out of the slot and move the barrel another ⅛" back up the tube such that you have to slightly force the end of the cable over the threaded pin....thus "pre load". Reason is to ensure that when "pushing" the center conductor, it has enough length to accomplish the required shifting force before you run out of cable movement.

 

[KEYCHS1720]

Hmm, Mercury owner's manual? The photo is from the manual I provided in the link. That's where I have been obtaining most of my information from, and it looks just like my setup. I attached a picture of it. Can you further explain "the barrel is position....you rotate the barrel such that shift shifter is comfortable in it's slot". Are you referring to moving the barrel adjuster on the threaded brass fitting of the shifter cable or adjusting the barrel within the barrel slot on the motor?

Is there a "known" or "factory" distance the shift pin and control pin should be from the center of their respective barrel housing on the motor? I've seen where "replacing control cable" instruction state measuring the existing distance and transferring that to your new cables but have yet to uncover anything providing factory defaults (for lack of better explanation).

Picture attached in PDF for greater resolution. Thank you for lending your brain!

 

[KEYCHS1720]

bump

 

[Texasmark]

I haven't seen one. Could depend on the cable mfgr. as to how long is the brass, threaded barrel, what kind of control you are using, this and that variable.

The barrel and plastic slot location is indicated right there in your photo with the shifter and throttle barrels fitting into the same plastic fixture, one above the other. It's not rocket science. Not meant to be demeaning, but it's straight forward: Shift the engine into neutral. Set the remote to N and wiggle to get it centered. Connect the tip of the center conductor to the shift post on the engines shift linkage and install the lock nut and flat washers if so equipped between the nut and the plastic tip of the cable.

Remove the plastic cover, covering the barrel's installation slot and rotate the barrel up or down the threaded brass outer conductor tip till it easily slides into the plastic slot. Pull it out and add a couple/few/some turns toward the control and test to see how it fits the hole...you want to force the brass barrel to move aft slightly putting slight pressure on the engines shift linkage. Keep trying this until you have to exert some/little bit of effort to get the barrel back in the slot, without forcing the engines shift linkage to move out of the N detent.

Put the barrel back in the slot and secure the cover . Go to the control and shift to F and back to N a couple of times. With it in N, you should be able to rock the engines shift linkage back and forth with your hand feeling that you are in the center of a trough so to speak, not on one edge or the other. If so, you either didn't go far enough to take up the slack, or you over compensated for too much slack that wasn't there.