How can I tell what engine I have???

sebas54

sebas54

Petty Officer 1st Class
Joined
Jun 17, 2007
Messages
334
I can't find the serial #'s and need to know what engine I have. I know it is a 1987 gm 175hp 4.3l

In my manual there is mcm model number 175 alpa/mr and 4.3l alpha/mr How can I tell which one I have. the only difference that I see is that the max WOT is different.

Thanks!!
 
Don S

Don S

Honorary Moderator Emeritus
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Messages
62,321
Re: How can I tell what engine I have???

Do you have a serial number tag over the starter?
 

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sebas54

sebas54

Petty Officer 1st Class
Joined
Jun 17, 2007
Messages
334
Re: How can I tell what engine I have???

I replaced the starter last year with a new one. I will check the engine #'s tomorrow.

Don,
I need to know this because I am only achieving 4000rpms with 18" pitch prop. I was told that this was under powering it but if I have the 175/alpha model then I would be within my recommended rpms(3800-4200).

Thanks
 
O

o-jay

Cadet
Joined
Jun 27, 2008
Messages
17
Re: How can I tell what engine I have???

Mine's an OMC, but it sounds like your manual is describing the same thing by two different names.

I have a 4.3L GM v6, and it's 175 hp. Like I said, mine's an OMC, but I think your manual's reference to 'alpha' is the Mercruiser Alpha One outdrive.

I'm kind of talking in circles, what I'm saying is it sounds like your engine is a 4.3 L GM V6 that is rated 175 hp, in front of an Alpha outrdrive.
 
Bondo

Bondo

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71,449
Re: How can I tell what engine I have???

Ayuh,... Is it a 2bbl. or 4bbl. Carb,..??
 
Don S

Don S

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Re: How can I tell what engine I have???

The reason he is trying to find out what engine he has is because of how Merc designates the engine by model number. In 87 it was called a 175, in 88 it changed to 4.3L. Which one it is, depends on the SN, not the drive or anything else.

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