Re: Nissan/Tohatsu 90hp year models?
Most of the 2-smoke 90's will have interchangeable parts. That said, get the actual model numbers. Should be of the format M90A (Tohatsu) or NS90A (Nissan) or something like that.
Tohatsu does not typically use year of sale or manufacture to delineate models, and a unit made in one model year could easily be sold in the next, so "year" doesn't mean a lot. Sometimes, an EPA compliance year sticker is mistakenly claimed to be the year of manufacture, which is also not necessarily correct.
Then, if the models are not identical, you can check Elvin's parts catalog listings at
http://www.internetoutboards.com/PartsCatalogMenu.htm to see if the motors are the same or similar. Sometimes there are running changes (based on serial number). If that's the case, it will be noted in the parts catalog, in the right column. HTH.