1976 Formula 351 Shifting problem

[Mrorak]

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OK i just bought a boat and it is my first. I don't really know much about boats as of now, but i work on cars and have worked on a 350 engine before. The boat has a 351 ford engine if you need more info on the boat let me know the bot is a thunderbird 21 foot. The guy i bought it from said the shift interrupter is not working and there is a wire leading from the shifter to the engine that needs to be replaced when the boat tries to change gears it shuts down. he took it to a repair place and they told him it was the shift interrupter. they were able to bypass it with another wire but that is all they told him he did not fix it. Now i am trying to fix it, does any one know how to fix this problem? please let me know i really want to get in the water and soon time is running out.

Thanks
Mike

 

[achris]

Re: 1976 Formula 351 Shifting problem

If it's a Mercruiser, then it sounds like you need a new lower shift cable...

Chris.........

 

[mkast]

Re: 1976 Formula 351 Shifting problem

Get your hands on the appropriate Mercruiser manual.
It will save you hours of work.

 

[Mrorak]

Re: 1976 Formula 351 Shifting problem

it is not a merch engine it is a ford 351

 

[Fishermark]

Re: 1976 Formula 351 Shifting problem

It is the outdrive they are talking about - not the engine. You need to give more info as to the outdrive you have.

 

[Mrorak]

Re: 1976 Formula 351 Shifting problem

ok where do i fin the out drive information i am sorry i am new to this boat thing.

 

[achris]

Re: 1976 Formula 351 Shifting problem

Look for the words "Mercury", or "MerCruiser" somewhere, usually on the leg itself or the transom plate... Outside the boat... The bit with the prop on it...

Chris........

 

[Mrorak]

Re: 1976 Formula 351 Shifting problem

it looks like the plate was painted over the only thing i can read is OMC 235hp

 

[achris]

Re: 1976 Formula 351 Shifting problem

it looks like the plate was painted over the only thing i can read is OMC 235hp

That's me gone

Good luck.

 

[Fishermark]

Re: 1976 Formula 351 Shifting problem

As you can see from achris' reaction, you have an OMC outdrive. They have been out of business for a long time... and no one uses Ford engines anymore. You have an old, obsolete system that hasn't been used in years.

That's not to say your setup is good or bad in and of itself... just that is is becoming increasingly difficult to find the various parts you will need. And even more difficult to find a competent marine mechanic who knows anything about it. Sorry, wish I had better news.

 

[gene8084]

Re: 1976 Formula 351 Shifting problem

ok where do i fin the out drive information i am sorry i am new to this boat thing.

My immediate reaction is this is not a switch problem, it's a problem with adjustment of your shift cable.​

If I'm right it is very easy to see the problem w/o the boat running.
1.) Pull the cover so you can see the shift and throttle cables where they meet the shift plate.
2.) Locate the shift interrupt switch. Left side of shift plate when facing aft. You'll note there is a nylon cylinder end on a SS arm. The nylon end should remain in the concave slot when shifting.
3.) Note the location in Neutral. If it's not in the slot - stop and adjust (see instructions) else...
4.) Shift to forward and check, shift to reverse and check.
5.) Move the Remote control past where shift engages and check.​

If in any of these conditions the nylon end climbed out of the slot you either have an adjustment problem or a cable that needs to be replaced. I can't advise how to determine if replacement is needed.​

Some instructions: http://amarket.com/f520.htm
Manual: Mercruiser Stern Drive Shop Manual 1964-1985 (get one)
http://cgi.ebay.com/Mercruiser-Ster...Z180285541120QQcmdZViewItem?_trksid=m20.l1116​

JUST SAW THE OMC update... not sure how much this will apply.
Try Amazon:
http://www.amazon.com/Marine-Engine...e=UTF8&s=sporting-goods&qid=1221583949&sr=8-1​

 

[achris]

Re: 1976 Formula 351 Shifting problem

My immediate reaction is this is not a switch problem, it's a problem with adjustment of your shift cable.​

If I'm right it is very easy to see the problem w/o the boat running.
1.) Pull the cover so you can see the shift and throttle cables where they meet the shift plate.
2.) Locate the shift interrupt switch. Left side of shift plate when facing aft. You'll note there is a nylon cylinder end on a SS arm. The nylon end should remain in the concave slot when shifting.
3.) Note the location in Neutral. If it's not in the slot - stop and adjust (see instructions) else...
4.) Shift to forward and check, shift to reverse and check.
5.) Move the Remote control past where shift engages and check.​

If in any of these conditions the nylon end climbed out of the slot you either have an adjustment problem or a cable that needs to be replaced. I can't advise how to determine if replacement is needed.​

Some instructions: http://amarket.com/f520.htm
Manual: Mercruiser Stern Drive Shop Manual 1964-1985 (get one)
http://cgi.ebay.com/Mercruiser-Ster...Z180285541120QQcmdZViewItem?_trksid=m20.l1116​

Dude, it's NOT a Merc, it's an OMC.......

 

[gene8084]

Re: 1976 Formula 351 Shifting problem

Dude, it's NOT a Merc, it's an OMC.......

Ah...dude (just saw the update and editted my reply)...let's play nice. Wasn't it u that said....if it's a MERC?​

 

[achris]

Re: 1976 Formula 351 Shifting problem

Ah...dude (just saw the update and editted my reply)...let's play nice. Wasn't it u that said....if it's a MERC?​

Yep, that was me .... I did say 'IF' and also I asked him what it was, because at that point he hadn't told us... And given that there are more Mercruisers out there than all the others put together, statistically that was the most likely....

Didn't mean to offend with the 'dude' comment... OK?

Chris.......

 

[gene8084]

Re: 1976 Formula 351 Shifting problem

All smiles!
I should have asked... Having a Formula 180, Merc 188 and having had the exact problem (I assumed).