Round nose midshaft in a 650 Square nose

[mideast67]

Has anyone ever seen or personally made a 701 midshaft work in 650 superjet? Im building up a SN SJ rightnow and needing a midshaft for it. i just happen to have 3 or 4 701 midshafts laying around. i know anything can be made to work with enough effort but im just curious if anyone has experience with this or has seen it done?

 

[jetfreak78]

It works. I did a RN midshaft in SN. Cant remember correctly, but IT will fit in the SN housing without Problems (diameter and length). I think i needed a new coupler on the midshaft side, because the SN midshaft is is smaller in diameter at the threatend end...

 

[jetfreak78]

Also, you can use the RN bearing and selas to rebuild a SN housing

 

[mideast67]

Thanks man that's good info! but I should have been more specific. I was asking about making the actual bigger 701 midshaft housing work in a 650.

 

[long beach local]

The mid shaft is the same and I think the bearings and seals might interchange but the 3 bolt pattern is smaller and won’t work and not worth effort moving and realigning the inserts in the bulkhead.

 

[SUPERJET-113]

90-93 SN 650 hulls have the 3 hull inserts to match the smaller mid shaft housing, 94-95 SN 701 hulls use the bigger mid shaft housing like in the RN hulls.

 

[long beach local]

90-93 SN 650 hulls have the 3 hull inserts to match the smaller mid shaft housing, 94-95 SN 701 hulls use the bigger mid shaft housing like in the RN hulls.

Thank you.

 

[Jr.]

I have done it. Use these threaded incerts from McMaster.
Make a template off your updated bearing support. Drill and epoxy in these incerts.
Only thing you will need to remember is use rtv or similar to seal your threads, as these incerts are not blind sealed

 

[Req]

I have done it. Use these threaded incerts from McMaster.
Make a template off your updated bearing support. Drill and epoxy in these incerts.
Only thing you will need to remember is use rtv or similar to seal your threads, as these incerts are not blind sealed

Sorry for reviving this:

I have a couple questions about the process I was hoping you could answer. I am planning on doing this on my 91 square project. I currently have the tray open, would it be advisable to build up some fiberglass on the backside where the new bolts and inserts will be? Also, how would you go about truing its alignment?

Thanks for the help.

 

[Jr.]

With the tray open, this is super easy! First off, upgrade the bearing support to the new style 95+
Remount your pump so you dont loose motor alignment. Mark your new hole locations from the bearing support mounted on the shaft. Do the build up like your stating. Install these incerts, and seal the backside
Of incerts from water getting into foam. This will have you very close for motor alignment once you are to that point after all your glass work. Fairly straight forward! Good luck

P