Mercruiser Engine ID - No serial number

[peters715]

I have looked everywhere from the starboard side around starter to under, back and port side. There is no tag or serial number to be found. The boat is a 69 Starcraft Starchief with a 1969 outdrive (serial number on outdrive indicates the year).

I was having problems trying to rig up the throttle linkage because I assumed the engine was a 1969 Mercruiser 120. After doing research the carb is a Mercarb, which I believe came along well after 1969 and explains why I could not find a throttle lever linkage for this config.

Also, the valve cover has a sticker with color codes for Engine Oil, Drive Oil, Engine Coolant and P/S Fluid. The intake/exhaust manifold is one piece while the earlier 120 intake bolted onto the top of the exhaust manifold.

The Mercarb has a 15397A4 2301 on the float bowl but I can not seem to find a date for this carb. The 15396 appears to be early 90's from what I have been able to glean.

So anyway, any thoughts on how to accurately date this engine without a serial number?

 

[alldodge]

I'm not able to find the carb number, you sure that's the number?

 

[peters715]

I'm not able to find the carb number, you sure that's the number?

Yeah, this whole beast is a series of contradictions.

 

[alldodge]

Made another search with a must have 15397A4 and found a carb listing in France on Rock Auto, but still no year. Could be the boat was once over seas

 

[peters715]

Made another search with a must have 15397A4 and found a carb listing in France on Rock Auto, but still no year. Could be the boat was once over seas

I found a rebuilder that has a couple of 15397's in their inventory but no info about year was listed in the description.

 

[Scott06]

That is a much newer cast valve cover with ribs on it. I had a similar valve cover on my 1991 vintage 3.0. So likely you have a newer 3.0/135 hp in there, which is not a problem, but is likely why you are missing the engine number ...might be a non Mecruiser replacement long block which again is ok...

Does the carb have only one idle mixture screw- this would also indicate a later Mercarb vs earlier Rochester 2 jet with two mixture screws.

Can you post a bigger pic of the whole engine you can likely rough in the year and serial number range off of the manifold (some had integral cast in ends otherers had bolt on endcaps), valve cover, and distributor/igniton type (points/DDIS/or Delco EST)

You can look through the various 140/3.0 etc engine parts drawings and likely match up what you have

MerCruiser Engine & Stern Drive by Engine Model

Lookup MerCruiser engine & stern drive by engine model and buy discount parts and accessories from our large online inventory.

www.marineengine.com

 

[peters715]

I found a rebuilder that has a couple of 15397's in their inventory but no info about year was listed in the description.

Yes, the carb has one idle screw on the base.

I don't have a good full shot of the engine, however digging through the images I do have I found this image. It's on the starboard side of the engine between the distributor and block. I suspect this is some lot number for foundry where the block was cast and not relevant to anything external from Mercruiser.

I'll post a few more shots of the engine later.

 

[peters715]

Ok, got some more pictures of the engine.

 

[Scott Danforth]

1991 or later 3.0

 

[alldodge]

EST started in about 95 for the 3.0
The 3.0 didn't start using the electric choke til just before they went to TKS

Find the flame arrestor number was used on the 470. Boat probably had a 470 and was replaced with the 3.0

 

[Bondo]

Ayuh,..... The other thread peters has on this,.....

I'd merge 'em, but it would be a mess,.......
Peters, one thread per topic,..... You coulda posted in the other one, insteada startin' a duplicate,.....
It woulda come back to the top,.....

 

[peters715]

Ayuh,..... The other thread peters has on this,.....

I'd merge 'em, but it would be a mess,.......
Peters, one thread per topic,..... You coulda posted in the other one, insteada startin' a duplicate,.....
It woulda come back to the top,.

I thought about it but decided the topic was different enough to warrant a separate thread. Your remarks are duly noted and will applied going forward.

 

[Scott06]

The 3.0 didn't start using the electric choke til just before they went to TKS

my 1991 3.0 had an electric choke on its mercarb Long before TKS

 

[alldodge]

my 1991 3.0 had an electric choke on its mercarb Long before TKS

Don't know what to say, looking thru BAM parts list I'm not finding an electric

 

[markhodges78]

If you look under fuel pump and carburetor the electric choke is listed for the 90-94 3.0

 

[alldodge]

If you look under fuel pump and carburetor the electric choke is listed for the 90-94 3.0

Post link

 

[Scott06]

Post link

MerCruiser 3.0LX GM 181 I / L4 1990-1995 Fuel Pump & Carburetor Parts

MerCruiser 3.0lx gm 181 i/l4 1990-1995 fuel pump and carburetor parts. Buy a genuine Mercury Quicksilver or aftermarket part.

www.marineengine.com

part #11 is electric choke element

 

[alldodge]

MerCruiser 3.0LX GM 181 I / L4 1990-1995 Fuel Pump & Carburetor Parts

MerCruiser 3.0lx gm 181 i/l4 1990-1995 fuel pump and carburetor parts. Buy a genuine Mercury Quicksilver or aftermarket part.

www.marineengine.com

part #11 is electric choke element

Going to need to advise further
One of the parts listed is a Sierra "aftermarket" part. Note that BAM and Mercury Marine do not list the E choke, only the dash pot

Not saying your not right, but if you use Mercury parts break down its not listed.

 

[Scott Danforth]

Pretty sure the dashpot went away for the 1991 and later motor. However there was inventory of the 1990 and prior

 

[markhodges78]

Post link

Can't post link to mercury parts look up but if you go to 90-94 3.0 it's under fuel pump