1990 Squarenose midshaft housing question

[Yamadogggy]

I have a 1990 square with a 61x 701 in it that I inherited a few years ago. The ski has been great with no issues, but I threw a new crank and pistons in at the start of this summer. When I had the engine out for that I noticed my midshaft housing bearing was making a grinding/rough sound. I threw it back together just to ride a few times this summer, but now I'm ready to attack that. I know according to JetManiacs thread on midshafts that 650s had a smaller weaker housing. When the previous owner put a 701 in my hull is the housing something that would have been changed or is there any way to tell what it is? Thanks!

 

[Kohldanielzimmer]

You can’t just mount up a 94-2020 midshaft assembly to a 90-93 squarenose hull. The whole housing is larger (on the later model) so only 2 of the 3 inserts would align for the bolts. I highly doubt they put in a new insert in the bulkhead.

 

[Sparkplug]

Both midshafts use the same bearings. So in theory the same strength is there. The later model midshaft has more rubber around the shaft. So in theory. It would last longer and dampen better.

Jetmaniac on here can get you a new midshaft housing, bearing kit, to rebuild yours. Or an entire rebuilt assembly ready to go. They are pretty simple to rebuild yourself though.

 

[Yamadogggy]

You can’t just mount up a 94-2020 midshaft assembly to a 90-93 squarenose hull. The whole housing is larger (on the later model) so only 2 of the 3 inserts would align for the bolts. I highly doubt they put in a new insert in the bulkhead.

All I needed to know, appreciate it