I have just purchased a replacement yamaha fuel pump for my 1990 FJ1200. Looking at it.. neither of the nipples are marked as to which is in and which is out. Any guidance? When the pump is mounted the nipples basically flat/horizontal and I am guessing that the one closest to the "inside" of the bike is the inlet and the one on the "outside" is the outlet. Any guidance is appreciated.
On mine, the one towards the inside of the frame (closest to the carbs) is the outlet to the carbs.
The one towards the outside of the frame is the inlet from the tank.
Here's a couple pictures of mine. In both photos I had the tank off, and the inlet hose removed.
(http://i859.photobucket.com/albums/ab154/firehawk068/FJ1200%20Projects/Valve%20adjustment-HID%20headlight-Heated%20Grips-etc/P5110049_zps4ec7d2ee.jpg) (http://s859.photobucket.com/user/firehawk068/media/FJ1200%20Projects/Valve%20adjustment-HID%20headlight-Heated%20Grips-etc/P5110049_zps4ec7d2ee.jpg.html)
(http://i859.photobucket.com/albums/ab154/firehawk068/FJ1200%20Projects/UNI%20pods%20and%20Cam%20chain%20tensioner%20gasket%2005-02-15/3616AC27-5275-48FC-9ECD-FBDE5FEE1933_zpsb8vsrxxu.jpg) (http://s859.photobucket.com/user/firehawk068/media/FJ1200%20Projects/UNI%20pods%20and%20Cam%20chain%20tensioner%20gasket%2005-02-15/3616AC27-5275-48FC-9ECD-FBDE5FEE1933_zpsb8vsrxxu.jpg.html)
Easy to check, plug it in turn the key on and put your finger over the pipes. The side that stops or slows the pump is the outlet.
On both my '89 and '90. Like Alan says, the inboard nipple is the outlet to the carbs and the outboard nipple is the inlet from the fuel tank.
Fred