Another what is my engine question

I have a mercury 150 that has an unreadable serial number tag and a reman block so, so no original serial numbers. Is there any way to reliably order parts for my motor? right now I just look at parts diagrams until I find something that looks like it should be right.
I appreciate any help, thanks,
Dave

Using the reman part number 812815R97 mentions,

Outboard Powerhead Remanufactured Outboard Powehead.
NOW AVAILABLE: Up to an additional two years of Major Assembly Protection (MAP) on select new or remanufactured outboard powerheads. MAP Coverage follows the factory provided one-year warranty period from date of purchase. Call Mercury Product Protection toll free at 866-521-2024 for program details. Replaces 1990 and newer Mercury or Mariner 135/150 horsepower 2.0 Liter V-6 engines with horizontal reeds. (s/n 0C239553 - 0G960499) Note: Block includes a fitting access hole for an oil-injection motion sensor. [ 2007 - Core Deposit: $ 800, Container: $ 0, $ Bounty: $ 0 ]

Mercury Quicksilver 812815r97 - Ph 135/150 2.0-rm Qpd=no Nla is equivalent to parts:
•878365T00 Mercury Marine
•878365A00 Mercury Marine

Additional information about this part can be found on page(s) 380, 382 of the Quicksilver Marine catalog.

Click to expand...

^ From here, http://www.marineengine.com/newparts/part_details.php?pnum=MER812815R97

Looking up the serial number range for this remaned engine model would put your parts within the following serial number ranges, http://www.marineengine.com/parts/mercury-outboard-parts/v150

By looking up the "offshore model name" for this model seemed to only be produced between 1997 and 1999 which helps narrow the parts catalogs you can use to cover all the years possible of the list above.

There seems to be only two parts catalog part numbers that fits the offshore models and they are Mercury part numbers 90-816098 96 which covers 1997 and 98 years then in 1999 the catalog part number went to 90-803170. In 2000+ the offshore name seemed to have went to Salt-Water but watch the decal sets because it says Blue Water in 1999 while 97/98 says Offshore.

http://www.marineengine.com/parts/m...0-thru-0g960499-usa/miscellaneous-information = http://www.marineengine.com/parts/mercury-outboard-parts/v150/0g760300-thru-0g960499-usa

http://www.marineengine.com/parts/m...6-thru-0g760299-usa/miscellaneous-information = http://www.marineengine.com/parts/mercury-outboard-parts/v150/0g303046-thru-0g760299-usa

With all that mentioned you ought to have an 97 or 98 using the following decal guide as they match yours, http://discontinueddecals.com/mercury_decals_150_offshore_blackmax1
http://discontinueddecals.com/store/Search.aspx?SearchTerms=150 offshore

And obviously you know the reman part is a 1999 with the date right there in the photo.

Hope that helps some, good luck.

Holley smokes. I can't tell you how long I have spent trolling around the internet trying to find this information. I should have joined this forum a year ago!
Thank you soooooo much boat_tech. I dont know how long this took you, I all I have ever found is pieces of information and have never been able to put them together. I will probably never know my exact numbers, but now I can confidently know which series to order from
Thanks again
Dave