Re: propeller shaft broke 89 125
Yes like Frank suggests, there are several on E-Bay, however, it's a little unclear as to whether or not they will fit. Much easier to replace the lower unit. There's a lot of them out there and I see some outrageous prices on them. Just be patient and you'll find one at a decent price. Craigslist is also a good place to look.
You can also use the lower unit from an 85HP from the same date range, however, you will have to increase your prop pitch. The original 125HP gear case has a 1.73:1 gear ratio. The 85HP motors have a 2:1 gear ratio. There is a benefit to this, as it will increase you hole shot and probably give you better overall performance. Some of the guys on this Forum including me have done this on purpose.
Starting in 1990, the factory started putting 1.93:1 gears in all the four cylinder Force gear cases. The four cylinder and 5 cylinder motors really like gear ratios in the 1.93:1 and 2:1 range. The 1.73:1 gear ratio loads the motor down just a tad too much in my opinion.