Help needed re shift linkage 1988 Force 125

docimastic

Seaman Apprentice
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Mar 8, 2015
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37
First, I want to say THANKS for all of the great info I've gotten from the members of this site! AWESOME!

Recently purchased for cheap a 1988 Bayliner with a 125 Force. Got it running on all 4 cylinders... a combination of defective CDI units and some defective wire to spade terminals on the ignition terminal block.

When we took the boat out, it would go into F /N / R but could give hardly any throttle in reverse. OK, could live with that... just had to be careful. BUT the last time out, after a couple of hours, it would not go into forward unless we quickly gave it full throttle... it would pop into F (fortunately before the engine had revved more than a tad... no violent engagement). I first checked the cable connection on the Morse type single lever control, and all looks good; no play or slop to speak of.

I then decided to check / set the shift linkage adjustment per instructions in factory shop manual and owner's manual (I have both! LOL) by marking the lower shift shaft first in full down / F positions, then full up / R position, and making a mark half way between those two marks... representing the middle shift rod travel ("mechanical neutral") and discovered that the Shift Arm Tab (Interlock Arm) - the piece attached to the upper **** rod - was sitting about 1/8" below the Tower Shaft Tab, instead of being aligned as they should be.

That explains why we could only give a little throttle in reverse. The tabs were hitting when in reverse. So, now my problem... After much PB blaster and putting the engine in reverse to raise the shift shaft to gain better access to the top adjusting nut, I was able to loosen / unscrew the upper adjusting nut of the shift arm tab. I can get an open end wrench on the lower adjusting nut, but can't budge it, despite much PB Blaster over a couple of days. I don't know if the nut (which is rusty) is rusted to the shaft (I have tried to turn it both ways) or if the aluminum shift arm tab is "locked" onto the shaft due to aluminum corrosion... or both.

I cannot get a straight shot at the lower adjusting nut... If I could take off the air intake baffle, my access to the nut would be better. But I can't get to the starboard rear air baffle bolt because of the shifter mechanism, and can't see how to remove that assembly. I have looked at quite a few pictures on Ebay of remove shift assemblies... but still can't figure it out.

Any help on that would be appreciated.... And, also.....

In Aug 2015 Frank Acampora talked of adjusting the linkage by spinning the lower shift shaft counterclockwise, starting with one turn (to raise the upper shift shaft.) https://forums.iboats.com/forum/eng...tboards/10013658-88-force-85-hp-shift-linkage . Thinking abut using this as a workaround to the above issues.

First, is the lower shaft supposed to spin fairly freely? When I was getting the holes lined up for the cotter pin (not an easy task!) the lower shift shaft sure didn't spin... at least, not easily. Second, and more importantly, the lower shift shaft has 1/2 inch of threads at the bottom, where it screws into the shift coupling. I am real leary about unscrewing the lower shaft 1/8 of an inch to use that method to line up the tower and shift arm tabs.

Again, any thoughts / comments / wuggestions will be much appreciated.

PS: Sorry this is so long...but I wanted it to be complete and accurate, and hopefully, clear.to understand.

David
 

docimastic

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Bump... Frank? Anyone? I suspect that SOMEONE, at a minimum. can tell me how to remove the air intake baffle... Thanks, David
 

jerryjerry05

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May 7, 2008
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17,923
Have patience, It's the weekend and some of us(me) can only get on here in the mornings.

The baffle, I use a 1/4" ratchet and a swivel and 5/16 socket. Or is it 1/4"??
That's always worked.
Maybe take off the lower carb cover?

That locking nut might need some heat when trying to remove it?

In extreme cases the shift linkage has been removed to gain access?

The lower shift shaft: once you start adjusting it? you can destroy the seal.
I'd leave it alone unless it's the only option you have.
There should be enough adjustment on the shift rod to do what you need.
If the seals new?
The shift rod I screw it in until it bottoms, then out 4 turns.
If nobody's worked on it? it shouldn't need adjusting.
 

docimastic

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Mar 8, 2015
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Thanks for your thoughts and comments, Jerry....!!

Ah, yes, patience is a virtue. Good point, and thanks for the reminder to be patient. I've gotten better in my older age (69) but obviously don't have it perfected!

Unfortunately, I know nothing of the motor's service history. The guy I bought it from only had it a few months, and pretty sure didn't have it in the water or test tank. Have tried without success to contact the owner prior to him. Lacking that knowledge, I am going to replace the water pump impeller (already have it) even though it pumps great. Don't want a vane to crack off and get up into the water passages!

Hey if you can get the air baffle off using a swivel, I ought to be able to, also. Thanks for that... and yes, 5/16. Oh, and I have both carbs off to replace the needles (so that part of access to the adjustment nut is not an issue) ... the rubber tip of the top carb needle was ever so slightly rounded ,,, presumably the cause of fuel leakage from top carb and rich running of #1 and 2 cylinders....and lack of full power / rpm. (3300 rpm at WOT).

Yes, strange about needing adjustment. As you said, if nobody has worked on it, it shouldn't need adjusting. I read a post (don't remember if on here or on the ME forum ...maybe it was a post of yours?) in which the poster said that in 25 years he had to only adjust the shift tab on one Force motor. Hmmmm. BUT your comment that you screw the lower **** rod in until it bottoms, and then back it out 4 turns makes me suspect that someone (maybe while doing an impeller change?) screwed the lower shift shaft in until it bottomed.and left it there. (I can easily imagine someone thinking, "oh, it's loose...let me screw it all the way in...) I'm not 100% sure of the thread pitch on the bottom of the shaft...but I found a really good pic of one on Ebay, set next to a tape measure....and it appears to be 1/4 X 20, 99% sure.. so 2.5 turns out would raise the shaft 1/8 inch....which is what I estimated (no, did not measure) the tab misalignment to be.

Thanks for the caution about possibly destroying the seal when unscrewing the lower shift rod a few turns. I will first try some heat on the tab adjusting nut and tab proper today (bought a new flare nut wrench... I'm afraid the open end might slip / round the nut!) But if I can't loosen / adjust it there, I am going to try unscrewing the lower shift rod a couple of turns. (Maybe see if it screw in first, then count turns out... reeeeeeely don't want to unscrew it from the gear shift coupling and have to disassemble the LU!)

If I do end up backing out the lower shift rod, I am thinking I will replace the seal for it when I change the WP impeller. That's assuming I can remove the shift shaft seal with the shaft still in place......

You have given me renewed hope re solving this issue! Thanks so much, Jerry! Hope your day is GREAT!

David
 

jerryjerry05

Supreme Mariner
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May 7, 2008
Messages
17,923
Good idea to change the shift shaft seal.
Again caution!!! the metal is old and can crack easily.
Make sure the mating surface is ABSOLUTELY clean.
Use a sealer that fills in all the area as any water in that area will cause the metal to corrode and squeeze the seal making the rod hard to move after a while.
 

docimastic

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Mar 8, 2015
Messages
37
Thanks for your additional thoughts/ comments, Jerry, including your caution. Yes, old... Like me! LOL, For clarification, what mating surfaces are you referring to re making sure absolutely clean?, The seal contact areas, or ?? And what sealer do you suggest? Water pump silicone or ??

I reeeeely appreciate your help, Jerry! I have rebuilt a Corvette motor (my first car, a '57 Vette!), rebuilt an automatic transmission that lasted longer than the one that the factory put in the car, rebuilt differentials, swapped out motors and transmissions in cars, you name it. Soooo, lots of experience turning lots of wrenches, BUT not so much experience with outboards.....

Thanks, again,
David
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
The surface where the seal sets.

I use OMC's gasket sealer.Mercury and Yamaha sells a similar product.
Part#
508235
Just brush it on.
One can lasts a long time.

A motors just a motor weather it goes on a boat or in a Vet.
The most important tool is a factory manual and the ability to ask for help when you "just don't get it".​
 

docimastic

Seaman Apprentice
Joined
Mar 8, 2015
Messages
37
I thought that that is the surface you were referring to, thanks, Jerry.. and Thanks for the part number, too!

And yes, re a motor is a motor... except of course for corrosion issues on marine stuff! LOL

Fully agree with your comment "The most important tool is a factory manual and the ability to ask for help when you "just don't get it"." Truer words were never spoken! When I buy a car (have several 15 to 20 year old ones) or boat engine (I've got a coupe of Suzuki's... a DT55 and a DT65) the FIRST thing I do is get a FSM!!

David
 
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