Super Jet Stock Head Question

C

ColtS

Location
Coarsegold, CA
Ok, So every water toy I took camping for the 4th came back broken. I need to get the SJ fixed before anything else. What happened is the ski is completely stock motor wise and the stock exhaust mounting studs on top of the head broke off. This is a 91 square nose 650. I bought a head from a local guy that came off another 650 SN. The head has "6R7-00" stamped on it, as does the intake of my superjet. The head is actually different from my stock head though. Did they make 2 different 650s in 90 and 91? The bolts actually may line up but it looks like I'll need longer head bolts to use the head I picked up. I want to keep this ski as stock as possible because it's the lender ski and everyone likes to learn to ride on it, so power isn't as big of a deal as reliability is. All of the stock heads I find on eBay are the same style as the one I already bought. Any ideas why my head would be different then all of the ones I can buy? I can get pictures just not until later today. The head that broke in the ski has the bolt size and torque specs stamped into it and it's the blue/grey color so I'm assuming that it's stock.
 
C

ColtS

Location
Coarsegold, CA
The head I bought was off of a friend that had a bone stock SJ that he swapped a 701 into. I guess someone could have swapped motors to a couch motor before he bought it but I think the odds of that are pretty low. His is a 1990 and mines a 1991, that's the only difference I've noticed. It's kind of weird that the head I bought has the same numbers stamped into it as my intake sticker.
 
H

hbski

Location
HB
6R7 is the earliest SNSJ stuff....maybe only '90? I've got piles of parts from the SNs if collected around here and I've go 6R7, 6M6 (the more recognised 650 SJ designation), 61x, 61T, 64U. SJs used all of these parts the 6m6, 61X & 61T designations Almost describe complete systems for the engine, but then other parts may still differ. I even have a coil with 6R8 which I believe was an early couch or blaster designation cause it has longer wires.

Pretty sure your 6R7 head will work just fine
 
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