Re: 1993 Mariner 90hp lower unit stuck in forward gear
rambler:
Here is the online service manual for your engine. Though yours is a Mriner, it is the same as the Mercury.
http://1manual.com/Mercury manuals/Service Manual PDFs/TwoStroke/13645_2/cover.pdf
If you scroll down to the lower part of the opening page, you will see the various engine components in red. Click on the one you want and when the first page opens, click on the "Save As" icon at the top LH corner of the page and you can save it to your computer.
Look under Gear Housing, page 5A-33, Installation Procedure.
The boat and the LU must be in the same gear before installation as you will see in the instructions.
Good Luck!
Gerry