1969 Mark Twain shift cable and parts problems

[BDUB09]

Hello all First off this project should have been done awhile ago but work got in the way. So here we go I have a 1969 Mark twain v16. 120 or 140 and model 1 outdrive.
First off up until about twenty minutes ago I was sold on it being a 120 because of the valve cover and the lack of any external balancing on the crankshaft confirmed by two marine shops.
The problem lies in finding the right parts, I ordered the wrong part thinking it was right, thus the situation I'm in now the cable was returned because it was clear it would never work (over a foot to long/ wrong end).
So we looked up the motor serial number and it comes back as unknown to there computerized number system but that only goes back to 1974.
The parts/service manager says don't worry we have old books that go back farther... after a half hour of digging through books he tells me it is a 1966 140 per the serial number.
I am having another shop look at it to confirm this, but I am going to throw the number out here for kicks. It reads 3937746 con 2 first line below that is g29 9.
Now I know all the parts are available here, but I have no part number to reference, if you guys or gals have tips for getting the right one I'd love to here them, I am looking for my camera at the moment as soon as it is found I will post pictures.

To sum it up I would like to know if you guys or gals no how to breakdown that number second would be parts availability and third would be do I have the right crankshaft pulley and if not where would I find one?


Thanks in advance

 

[Bt Doctur]

Re: 1969 Mark Twain shift cable and parts problems

Mercruiser Schematic Part Diagrams going by that number 72-78

 

[BDUB09]

Re: 1969 Mark Twain shift cable and parts problems

So is it a 120 or 140 because the 1972-1978 120 and 140 numbers are almost identical Thanks in advance for your help

 

[Bt Doctur]

Re: 1969 Mark Twain shift cable and parts problems

take some pics and post them.

 

[BDUB09]

Re: 1969 Mark Twain shift cable and parts problems

So they all suck I know the first three show the motor in question the last two show the shift arm with cable seized into it... the end of the cable is visible there in the pictures as the second bump below the half moon key on the flat end of the arm... the very first pic is my best close up of the crank pulley it is the lower of the two the upper is the cam idler pulley or whatever you call it ... lol

 

[achris]

Re: 1969 Mark Twain shift cable and parts problems

...
The parts/service manager says don't worry we have old books that go back farther... after a half hour of digging through books he tells me it is a 1966 140 per the serial number.
I am having another shop look at it to confirm this, but I am going to throw the number out here for kicks. It reads 3937746 con 2 first line below that is g29 9.
Now I know all the parts are available here, but I have no part number to reference, if you guys or gals have tips for getting the right one I'd love to here them, I am looking for my camera at the moment as soon as it is found I will post pictures.

To sum it up I would like to know if you guys or gals no how to breakdown that number second would be parts availability and third would be do I have the right crankshaft pulley and if not where would I find one?


Thanks in advance

OK, a few things jump out....

1. No 140hp 4 cylinders in 1966, they didn't start until 1968.
2. That serial number comes back, for me, as a 1974. Can't tell you what engine though, sorry. But the serial number (if it's a Mercruiser engine serial number) is most definitely 1974.

Look for a code on the engine block either 'NB' or 'RA' (it might not be there...)

Hopefully there's some numbers on the carburetor. If you can find all those, I might be able to give you a better idea.

Chris.....

 

[achris]

Re: 1969 Mark Twain shift cable and parts problems

View attachment 209121View attachment 209122View attachment 209123View attachment 209124View attachment 209125 So they all suck I know the first three show the motor in question the last two show the shift arm with cable seized into it... the end of the cable is visible there in the pictures as the second bump below the half moon key on the flat end of the arm... the very first pic is my best close up of the crank pulley it is the lower of the two the upper is the cam idler pulley or whatever you call it ... lol

SCARY!!!

#2 photo shows a plastic in-line fuel filter... VERY dangerous. Please remove that and put a proper water separating filter in the line before the fuel pump.

Here's the good news.... Despite the poor focus of the photos I have identified your engine...

It's 120hp (153cu.in) in the serial number range 1666601 to 1725592... I suspect that manifold is aluminium (not cast iron), correct? That puts it as 1964....

The first photo, is of the crank pulley, the water pump pulley and the alternator pulley...

Now the bad news... The crank pulley, part# -35602, is no longer available from Mercury... I did find a couple on eBay... http://www.ebay.com/sch/i.html?_odk...TRC0.X35602+pulley&_nkw=35602+pulley&_sacat=0

Sorry about the incorrect info in the previous post, hadn't seen the photos at that point. :facepalm:

Chris.....

 

[BDUB09]

Re: 1969 Mark Twain shift cable and parts problems

Thank you for the replies the boat has been out of water for over ten years. I picked this up boat up around the 1st of July and have been trying to make it right little by little as we go.
Now as far as the serial numbers the number i gave you was stamped on the block it is 7 digits the problem really came in title and registration... boats that old have no stamped i.d. into the hull just a tag identifying hull number and motor number( so I was told correct me if wrong) now the last time the boat was registered here in WI. they used both numbers at which time matched. And in trying to get it re-titled and registered I was told it would have to be registered as home built due to the numbers not matching... I think I may just tell a white lie next time I go in
now the number on the block (3937746) does not match the original motor ID number stamped on the tag (1825438) does that mean I don't have the original motor... I know it seems like a dumb question but in cars that would mean the motor isn't original. And I only ask because you referenced numbers that my block number would not fall into.
More info the manifold is aluminum but cant guarantee it is correct as I have three manifolds and three carbs. one cast two aluminum.
A little bit of back story the owner before me was the original owners son. The original owner began to restore the boat but health problems came about and he stopped with the hull gutted. Here's where it gets interesting the son decided to sell it and with no knowledge of boats he decides to re-install the motor out drive and interior along with the controls. Now the controls never worked since the seized cable. The motor ran but needed a lot of help I have that basically dialed in. I went on to the out drive including replacing bellows water pump gimbal bearing and shift cable.
Now were back to my current point needing parts and having ordered the wrong ones once I am a little pokey about ordering more until I know exactly what I have got.
Now as for numbers on carb/intake I have been told of these before where do I find them I haven't been able to locate any numbers up to this point.

Sorry if I missed something hectic day
Thanks much for your help

 

[achris]

Re: 1969 Mark Twain shift cable and parts problems

ok... so we add more to the mix.. Grist for the mill... Love it

The number 'on the block' (3937746) is a casting number. A number used by GM in the factory. Unfortunately it has the same format as the early Mercruiser engine serial numbers :facepalm:... and that's what I called the 1974 on. Sorry about that...

You found a Mercruiser tag with 1825438 on it... Good start. That engine serial number is probably from 1965.

It's quite possible the PO did put an earlier manifold on, hence my 1964 verdict. They are basically all interchangeable in that era. I would run with 1825438 as the engine serial number, and it is a 120hp (153 cu in) engine...

HTH,

Chris.......
BTW, that pulley number is still valid....

 

[BDUB09]

Re: 1969 Mark Twain shift cable and parts problems

Thanks Chris. Any thoughts on getting the shift cable out of the shift arm it appears to be seized in there the arm move freely but the cable does not slide in its sheathing. It is shown in the pictures above.

I am new to I/O's so all your help is greatly appreciated.
Thank you to all in advance.

 

[achris]

Re: 1969 Mark Twain shift cable and parts problems

If you need to replace the cable, it comes as a complete assembly. Just cut the old one... Just make sure you can buy a new one first... (they are still available from Mercury, but you will need to recover the slide off the drive end, and the guide off the engine end.)

Here's a copy of the factory manual for your engine...

Service manual

 

[BDUB09]

Re: 1969 Mark Twain shift cable and parts problems

The slide is seized to the cable and at this point in time I cant find a replacement cable the boat and I just visited 4 shops mercruiser certified that couldn't find the right one... Now that you mention the guide if I can indeed disassemble that I may have located a cable

Again thank you so much for your help.
I don't know about you but this is starting to get entertaining for me in the fact that better, more helpful information has come from someone thousands of miles away than right here in my own back yard :thumb:

 

[BDUB09]

Re: 1969 Mark Twain shift cable and parts problems

I have located a new shift cable and it is now on order I hope to see it Wednesday. I will keep everyone informed on how it goes, I choose to not order the seal kit for one reason they wanted 280 for it I thought that seemed steep it includes the (gimble bearing, all bellows, water tube, and gaskets).
Thank you again for your help

 

[achris]

Re: 1969 Mark Twain shift cable and parts problems

Just out of curiosity, what's the part number of the cable you've ordered? (I think it should be -35187A4, which supersedes to -73723A01)

Also at that age, I would replace the shift cable bellows at the same time. Just the act of pulling the old cable out might be enough to tear the old bellows... (part# -31659, supersedes to -74639A2)

Cheers,

Chris......

 

[BDUB09]

Re: 1969 Mark Twain shift cable and parts problems

First off all the bellows are getting replaced that was the main initiation of this project the exhaust bellows had a gaping hole and you know how it goes the farther you dig the more problems you find :facepalm: nothing you can do about that though. Other small things are I plan to inspect the water pump impeller, I'll probably just change it because then I know exactly whats in there. I intend to replace the gimbal bearing and I'm concerned about the corrosion that has formed on the bearing surface. The u joint bellows were undamaged and its been out of water for over ten years. Could that rust be from storage or should I look into resealing the transom plate/ gimbal mount, I also plan the check engine alignment.
I don't have a Mercruiser number I forgot what it was though I have its cross reference number for a teleflex cable it is SR18.290

Thank you for the manual it has already provided me with plenty useful information.