Confused about Mercruiser model years

[jsw102503]

I had posted yesterday about some flapper issues. I'm trying to order some parts and I can not get the engine serial number which is making the process difficult.

I purchased the boat used 1.5 years ago. I believe it went through a few owners. The serial number section of the flame arrestor is blank. I can not access the serial number plate on the starboard side of the engine because the boat is a walkthrough transom and the area is EXTREMELY constricted. I've tried putting cameras back into there and blindly snapping photos and have not had luck.

The boat is a 2003 Caravelle 187. It has a 4.3L Mercruiser with the Thunderbolt V ignition system. It is carbureted. That is where my confusion comes in. All of the parts sites list the last year for a non-MPI or TBI engine as 1998. Would mine be the "4.3LH (Gen+) (4 Barrel.) GM 262 V-6 1998"? I have read that the MPI or TBI was introduced in 1999. Did they use a 5 yo motor in a new boat? Or did this boat get a new (used) engine at some point in its life and get an older engine put in? Mainly I'm trying to figure it out so that I can order parts and receive the right stuff.

Happy 4th of July and thanks in advance.

 

[Rick Stephens]

I have a morphodite mixed year motor. I usually tend to go through the different year 4.3L parts drawings and find the same parts as match my motor. Sometimes I use the later model motor parts, sometimes the earlier. Usually you can tell just by what carburetor and fuel pump is installed. You are probably safe using the 4 BBL carbed motor parts list for almost everything based on your guess - match ignition and carburetor and the list is going to be pretty close...

 

[QBhoy]

It’s a minefield with the 4.3...but the factory fit 4.3 for a 2003 would usually be a vortec carb or the not long released (at that time) mpi. There was a carb 4.3 tks around And after that year too.

 

[achris]

A 2003 4.3L is going to have a serial number in the range 0M365392 to 0M656796.

And yes, 4.3L had a 2bbl carb, and continued production right up to the point where Merc stopped using GM V6 and SBC V8 engines...

Your shutter part number is -807166A1, and you need 2 of them.

Chris.......