Question about swapping a Yamaha 760 into my 1990 SN Superjet

[TehXshizzit]

Hey all,

I am swapping a 760 into my square nose superjet, and I am having some trouble.

The main problem right now is figuring out how I swap a 5 finger coupler on my mid shaft, or how do I convert it in general.

Also I have heard I cant fit the stock air box in a SN, is that true?

Can you all post some pictures of your swaps for insight?

Thanks

 

[orangefinger]

utilize either 5 finger couplers on both sides or 3 finger couplers on both sides

remove the mid shaft , remove the coupler with from the midshaft

stock air box I assume u mean the stick flame arrestor box for dual 44's ?

would suggest to run aftermarket flame arrestors anyway

couple of things on the side and if u want to get the most performance
760 has more power but different ports less low end more mid to top best combo 62t/61x
760 electrics are also not as advantageous as 701 's ...

 

[TehXshizzit]

well the problem/question is, if there is a 5 finger coupler that will work on a Stock SN mid shaft? because the 5 finger I got from my parts guy so far was ment for a big thread. (1") instead of .75" that my SN has (small thread)

 

[Quinc]

The midshaft on the SN has different threads then the 96+ superjets. You will need to swap the coupler on the engine side. Will need to hold the flyweel or the piston to get it the old one off. Heat and a long breaker bar will help.

*Keep the 760 electronics and get a zeeltronic adjustable cdi.

 

[TehXshizzit]

I have been looking into the zeeltronic CDI, im guessing there is no 5 finger coupler out there that will fit my mid shaft.

 

[Quinc]

I have been looking into the zeeltronic CDI, im guessing there is no 5 finger coupler out there that will fit my mid shaft.

Couplers are cheap. @Rdrttoy probably has one.

 

[ArsenalR]

http://www.x-h2o.com/index.php?threads/square-nose-epic-billet-drive-couplers.192891/
This thread just made me realize that i purchased some Cold Fusion couplers for my SN and i think ill be running into the same issue..

 

[High Speed Industries]

The SN generally runs a smaller thread on the midshaft. It would be easier to just put a 3 finger coupler on the engine and be done with it. I have tons of 3 finger couplers if you need one. Just shoot me a message to get dialed in.

 

[lextreme]

http://www.x-h2o.com/index.php?threads/square-nose-epic-billet-drive-couplers.192891/
This thread just made me realize that i purchased some Cold Fusion couplers for my SN and i think ill be running into the same issue..

Measure the threads on midshaft to be sure... I purchased a set from Epic in that link... Went to go put it on my 1990 midshaft and found out I have the bigger shaft... More than likely when I bought a new midshaft from Jetmaniac he installed the bigger/ newer midshaft design and I didn't even notice since I purchased it ready to drop in with coupler and all...luckily Freestyle 650@ Epic had an EXTRA RN Sized midshaft coupler sitting around that I purchased... Now I have a small threaded SN Epic billet coupler I need to sell! Utilizes Kawasaki dampner like other aftermarket couplers.. Lol

 

[ArsenalR]

Measure the threads on midshaft to be sure... I purchased a set from Epic in that link... Went to go put it on my 1990 midshaft and found out I have the bigger shaft... More than likely when I bought a new midshaft from Jetmaniac he installed the bigger/ newer midshaft design and I didn't even notice since I purchased it ready to drop in with coupler and all...luckily Freestyle 650@ Epic had an EXTRA RN Sized midshaft coupler sitting around that I purchased... Now I have a small threaded SN Epic billet coupler I need to sell! Utilizes Kawasaki dampner like other aftermarket couplers.. Lol

That could be my dilemma too, I had JM rebuild my midshaft, Ill have to look at the invoice and measure...