Someone Identify my Outdrive for me?

JFLS40

Seaman Apprentice
Joined
Jun 29, 2004
Messages
39
Could someone identify the type of outdrive I have so I know what to look for when shopping for used parts. IS THIS AN ALPHA, PRE-ALPHA, MR1? WHAT? I NEED NEW UPPER GEARS AND RESEAL KIT. WANT TO MAKE SURE I GET RIGHT PARTS.<br /><br />Here is the information I can provide:<br /><br />1977 Seastar<br />Mercruise Sterndrive<br />#4525617<br /><br />Engine Serial No. 4503258 inline 4 cyl.<br />GM 140HP
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Someone Identify my Outdrive for me?

It's what's known as 'MC-1'. Most parts will be superseded to the alpha parts, particularly gears, which are stronger.<br /><br />The gear set part number is 43-55778A3 and the seal kit is 26-32511A1<br /><br />Chris...........
 

JFLS40

Seaman Apprentice
Joined
Jun 29, 2004
Messages
39
Re: Someone Identify my Outdrive for me?

I was under the impression this might be a "Model 120/140"? Is that a possibility?
 
Joined
Aug 1, 2004
Messages
7
Re: Someone Identify my Outdrive for me?

rounded cavitation plate is pre-alpha , square is alpha one. <br />eye hole at top of upper denotes pre-alpha also , flat plate that covers top gears is alpha , lastly , ribs around the gear oil check screw is a pre-alpha , and flat is alpha one. <br />120-140 would be the engine group , i believe the only difference in the drives would be upper ratio , 120-140 would be 1.98 to one ratio.
 

Puppet boat

Cadet
Joined
Jun 9, 2004
Messages
9
Re: Someone Identify my Outdrive for me?

Blk-n-Blu <br /><br />Great site. Do you know of a site for OMC
 

JFLS40

Seaman Apprentice
Joined
Jun 29, 2004
Messages
39
Re: Someone Identify my Outdrive for me?

What is the "MC-1" spoken of by achris? Is that another name for "pre-alpha"? I have the eyehole on the top of the upper, but not sure what the cavitation plate is?
 

Ralph 123

Captain
Joined
Jun 24, 2003
Messages
3,983
Re: Someone Identify my Outdrive for me?

Pre-Alpha = Merc #1 = #1 drive = "R"<br /><br />Lifting eye = pre-alpha= #1. Alpha 1's have flat tops and no lifting eye. The sides of the upper drive, near the top, is flat on Alpha 1's while Pre-Alphas have groves/ribs<br /><br />A cavitation plate is that horizontal plate (parallel to the ground) above the prop. Pre-Alpha is rounded on the end while a Alpha 1 is nearly square. Checkout the pics in the link given above and repeated here.<br /><br /> http://www.mercstuff.com/drive_id.htm
 
Top