Midshaft Talk - Building, Rebuilding, SN vs. RN, etc.

[derek93sn]

will all fx1 midshaft and housing will work in a rn

 

[RMBC Freeride]

will all fx1 midshaft and housing will work in a rn

No - only the Housing will work in a RN. The shaft will be far too short.

 

[kevbo]

We have three original 1993 650SJs with small housings. New ADA couplers fit perfectly.

 

[torfinn91]

I have a superjet 650d that has been put down a 61x engine (701)
I do not know if the jet system is orginal.
Is the jet pump housing diameter the same on 650 90-93 as the 701??

 

[JetManiac]

I have a superjet 650d that has been put down a 61x engine (701)
I do not know if the jet system is orginal.
Is the jet pump housing diameter the same on 650 90-93 as the 701??

Pump is the same size (144mm) in all superjets.

Only midshaft housings are different between 650 and 701.

 

[///M5]

Where is that midshaft comparison chart? I cant find it and I know its out there.

 

[Kohldanielzimmer]

http://www.x-h2o.com/threads/111971-Midshaft-length-and-fitment-master-list

^ lol this was in the thread on page 1. Is this what you're looking for?

 

[///M5]

^ lol this was in the thread on page 1. Is this what you're looking for?

LOl! Thank you, I was racking my patience looking for that chart and its right there WTH!

 

[2lick]

I just pulled out a bad mid shaft from my new ski this weekend and I'm looking to rebuild it, something I have never done before.
Thanks for making this write up, its great information!

 

[pmos]

Just replaced my midshaft housing + bearing on a 93 SN. Stock hull, so set press thru to 20mm, but when I run the ski, the midshaft gets super hot (too hot to touch). I greased the shaft and pumped some thru the zerk fitting.

Any ideas?

 

[kevbo]

All mine get too hot to touch. Seal drag makes heat and the shaft/bearing is insulated in rubber.

 

[pmos]

kevbo: thx. My 96 SN with an old midshaft housing was staying cool, so I thought I had a problem with the new one on the 93. Maybe the 96s seals are slightly looser, as I think it original.

 

[JetManiac]

kevbo: thx. My 96 SN with an old midshaft housing was staying cool, so I thought I had a problem with the new one on the 93. Maybe the 96s seals are slightly looser, as I think it original.

There is no 96 SN? The seals are the same on all SJs. Have seen the dbl lipped seal on the front in some couches and blasters which seem to create extra heat.

 

[catpower]

On a blaster there are only two shafts correct.1. Midshaft ( connecting coupler to driveshaft) 2. Driveshaft ( shaft impeller mounts to ) if I need a driveshaft for a waveblaster 1 is there another yamaha ski that uses same shaft or am I stuck looking in the bone yard?

 

[JetManiac]

On a blaster there are only two shafts correct.1. Midshaft ( connecting coupler to driveshaft) 2. Driveshaft ( shaft impeller mounts to ) if I need a driveshaft for a waveblaster 1 is there another yamaha ski that uses same shaft or am I stuck looking in the bone yard?

WB1 driveshaft is a unique length not found on any other ski.

 

[pmos]

JetManiac: Sorry, is really a 95 SN. Thx to you want kevbo, happy riding this weekend with hot midshafts.

 

[pmos]

JetManiac: Sorry, is really a 95 SN. Thx to you want kevbo, happy riding this weekend with hot midshafts.

Oops, should have read "Thx to you AND kevbo". Must be too much riding tonight!

 

[Christian_83]

May i add to the post my recent discovery about midshaft housings.
I found that most yamaha couches uses the "same" midshaft housing as SJ, just sitting on a larger bracket housing. See picture

You can unbolt this, press your SJ or custom midshaft in and mount it, ride and be happy. But what i found out, is while it appears to be identical, the internals has changed a bit, only running single double lipped seal in the rear (sj runs 2 seal, 1 single lip and 1 double lip in rear)
This could cause some confusing (it did for me)

Superjet:


Gp 1200

 

[txsuperjetfreak96]

Rn midshaft housing will work in a sn?

 

[BruceSki]

94-95 has same housing as rn