First boat with an I/O engine (Trim Question)

[tmking66]

I recently bought a boat with an I/O engine/drive. I have owned outboard boats for many years. This boat is a 1975 Scat Craft 21 foot cuddy cabin. It needs some work but I got it cheap. I am starting with the trim switch. First question: on my out boards there was just two trim buttons one for up and one for down. This one has three top button says up bottom says in I can't remember what the middle button said right off. I am assuming that the top button raises the drive and bottom button is supposed to lower the drive. What is the function of the middle button. Right now the drive is in the full up position. The top and bottom buttons don't do anything right now. When I press the middle button the hydraulic pump turns on but the drive does not move. There are 4 hydraulic lines going into the drive unit. I have not figured out exatly what drive I have yet as it is covered with several layers of black paint. I am pretty sure it is a mercruiser and it has the lifting ring on top of the drive unit. Next question: the engine in this boat is an 8 cyl. ford. How do I tell if it is a 301 or a 351? I am sure I will have many more questions before I get this thing back into the water. Thanks in advance.

 

[DuckHunterJon]

Re: First boat with an I/O engine (Trim Question)

Not postitve at all, but some systems have a separate button for trailer. So trim up, trim down, and trailer. The trim up will only come up so far, in order to prevent the ujoints from binding. When you want to raise it further than that for trailering, you hit the other button. This is how my 92 Glasstream was. Again, yours may be different entirely, not sure.

Also, if the motor is a ford, I doubt it's a mercruiser drive. Most likey OMC Cobra.

 

[Me1stBoat]

Re: First boat with an I/O engine (Trim Question)

My best guess without seeing any pics or having more info on the engine / lower unit would be that the 3rd button is a trailering button.

Mine has trim up / down and a 3rd button that says trailer. The outdrive has a limiter switch on it that won't allow you to raise the drive too far underway and lift the lower drive out of the water. This 3rd switch is for once you have it on the trailer to override the limit switch and raise the lower unit all the way up as to not drag the skeg on the boat ramp.

As for id'ing the motor, should be a motor and transom serial number on there somewhere, should help you definitively id your boat / lower unit combo!

 

[tmking66]

Re: First boat with an I/O engine (Trim Question)

"Also, if the motor is a ford, I doubt it's a mercruiser drive. Most likey OMC Cobra. "


I was assuming Mercruiser because the throttle control at the helm says mercruiser.

 

[ezmobee]

Re: First boat with an I/O engine (Trim Question)

Also, if the motor is a ford, I doubt it's a mercruiser drive. Most likey OMC Cobra.

Nope, there were Ford Mercruisers. V8's especially.

 

[Silvertip]

Re: First boat with an I/O engine (Trim Question)

Distributor at the front of the motor it's a Ford. Distributor at the back of the motor it's a GM (except for the Buick-built V6's). I owned a 1979 Century with a 351 Ford engine and as I remember the manifold had 351M cast into the intake manifold. The "M" standng for "Michigan" rather than "W" (Windsor) or "C" (Cleveland). But that is 30 years ago. A lot of stuff has passed through this old brain in that time.

 

[Maclin]

Re: First boat with an I/O engine (Trim Question)

OMC Cobras did not show up until later 1980's.

 

[Don S]

Re: First boat with an I/O engine (Trim Question)

It needs some work but I got it cheap.

LOL ......... You do realize the words that usually end of following that kind of statement are
"OMG What have I done"

Since you don't have a clue what it is, here are a couple of outdrive pictures, which one looks like yours?

 

[tmking66]

Re: First boat with an I/O engine (Trim Question)

I am getting pretty sure it is a pre Alpha R drive. I knew what I was getting into when I bought it. I was kind of looking for a new project. I just want to know exactly what I've got so I can get the right manuals to repair any problems to show up. For what I paid for this boat I can sell the trailer (good condition) and take the engine and outdrive to the scrap yard and make a profit.

Does anyone know where the serial number on the engine should be located??

 

[Me1stBoat]

Mine are on a plate on the valve cover. Engine & transom serials.

 

[mr 88]

Re: First boat with an I/O engine (Trim Question)

With the lifting ring it would be a Mercruiser type 1...

 

[cavalier858]

Re: First boat with an I/O engine (Trim Question)

3 buttons vertically in line on dash. On our Mercruiser type 1, 120/140 the top button raises the drive for planing. The bottom button lowers the drive. You need to push at the same time the top and center button to raise the drive up to trailer position.

 

[Me1stBoat]

3 buttons vertically in line on dash. On our Mercruiser type 1, 120/140 the top button raises the drive for planing. The bottom button lowers the drive. You need to push at the same time the top and center button to raise the drive up to trailer position.

Your trim buttons are in the dash?? Wow, never seen a setup like that!!

 

[old trophy]

Re: First boat with an I/O engine (Trim Question)

my 1985 fiberform had the same three buttons in the dash and I had to push both the middle and top ones together to raise the leg up for trailering.

 

[tmking66]

Re: First boat with an I/O engine (Trim Question)

Ok, back to the trim on this boat. I am getting ready to start reparing the trim. The outdrive is in the full up position. There is power going to the trim pump and the switches. When I press the center button I get a loud buzzing sound and no movement. The top button does nothing. When I press the bottom (in) button there is no movement or noise but I do notice a pull on the volt meter. Any ideas about where I should start. Tempted to just pull the pump out take it apart, clean and reassemble and see what happens but maybe there is some common causes for the trim not working.

 

[tmking66]

Re: First boat with an I/O engine (Trim Question)

Thanks for the wiring diagram!!! That should help a lot. I hope the pump is ok but it is a pretty harsh noise it makes when I hit the center button. Much louder than any trim pump I have ever run into but I'm keeping my fingers crossed that it is just electrical issues.

 

[tmking66]

Re: First boat with an I/O engine (Trim Question)

In looking at the distributor clips this afternoon they are at least an inch below the intake manifold. So does that make it a 351 for sure?? I can't really find any serial numbers anywhere.

 

[Don S]

Re: First boat with an I/O engine (Trim Question)

Just post some pictures of your engine and drive, that would make things so much easier.