Need year and Serial Number purchased used boat

I recently bought a boat prodject I need help with the following.

I don't know the year of a 50 hp Mercury (with red strip on bonnet). I have looked every where fpr the serial/model numbers, block, breaket, ect.
Its a three cyl. The trailer is a 1985 that the boat sets on.
the boat has set outside for 4 years I'm changing fuel lines, filters, case oil and many things in the hull of the boat.

Thanks in advance
Jim

Re: Need year and Serial Number purchased used boat

From the following link; MERCURY OUTBOARD MODEL YEAR GUIDE 40 HP (4-CYL) - 50 HP -- Mastertech Marine you can see that the 3 cylinder Merc motors were made from 1986 to 1996. This also shows that the 1985 modlue was a 4 cyclender. A Seloc manual, Volume II 1965-1992 3&4 cylinder, has info on the motor that should give you a good idea as to the vintage of the motor. It also shows that the 60hp motors of the time frame has the same bore & stroke as a 50 hp motor. With the red band motor it would be in the early years of production, BUT with everything not having any SR# nor Mod# then anything is possable. Sounds like you have a possiable Frankenmerc as some PO has done extenive work on it and has removed all the info of any form. JMO
Oldman570

Re: Need year and Serial Number purchased used boat

Thanks this will help me get a window. I have all serial numbers of the eng.parts trying to cross reference them.

Jim