Well I don't have as much info on the 750 as I posted in the 1127 but I did learn some good stuff (all for pre 98 750's). To start it is the same as the 88/89 gsxr engines. It has the big valve head commonly refered to as "the slingshot head" (29/25 mm valves, small combustion chambers). The only difference I've found to date is color (gsxr gray, kat black) and cams. It appears they took the gsxr exhaust cam and made it the katana intake cam and gave the katana a puny exhaust cam. Here's the specs on the gsxr cams (HARD TO FIND INFO)
Intake: .355" lift, 248 degrees of duration @ .040", 244 @ .050"
Exhaust: .334" lift, 242 degress of duration @ .040, 238 @ .050"
The intake cam I just pulled out of the katana motor I have measured .330" lift so I'm guessing they're the gixxers exhaust cam. It seems the gsxr cams are good for 6hp over the katanas so if you want gixxer cams just buy the 88/89 gsxr intake cam ($140 from ronayers.com) swap your intake to exhaust and your in the good for cheap. The only thing I'm still looking to see if the 88/89 gsxr has the same carbs as the katana. So essentially you can take anything off the 88/89 and bolt it into you katana motor.
Transmission upgrade
If you want a better transmission (katana trannys are junk) you can upgrade to a gsxr 1100 tranny (86-88 or the 1052 transmission). The gears have more cross sectional area and the tranny over all is a more rugged design. The only drawback is you will have a 5 speed, not a 6. To do the swap you need the shift cam, shift shaft, 3 shift forks and both gear shaft assemblies, the rest is the same. I'm currently doing the swap and will post pics of the trannys next to each other so you can see the difference.
I have a great article of a guy who make a stroker motor using the bottom end of a 91/91 750 and the top end of the katana/gsxr engine. I'll try to attach it: o.k. it's to big but essentially he got 122hp. If anyone want the article I can email it to you, just post you address.... Well this is all that comes to mind at the moment..
Intake: .355" lift, 248 degrees of duration @ .040", 244 @ .050"
Exhaust: .334" lift, 242 degress of duration @ .040, 238 @ .050"
The intake cam I just pulled out of the katana motor I have measured .330" lift so I'm guessing they're the gixxers exhaust cam. It seems the gsxr cams are good for 6hp over the katanas so if you want gixxer cams just buy the 88/89 gsxr intake cam ($140 from ronayers.com) swap your intake to exhaust and your in the good for cheap. The only thing I'm still looking to see if the 88/89 gsxr has the same carbs as the katana. So essentially you can take anything off the 88/89 and bolt it into you katana motor.
Transmission upgrade
![Very Happy](https://katriders.com/core/images/smilies/icon_biggrin.gif)
I have a great article of a guy who make a stroker motor using the bottom end of a 91/91 750 and the top end of the katana/gsxr engine. I'll try to attach it: o.k. it's to big but essentially he got 122hp. If anyone want the article I can email it to you, just post you address.... Well this is all that comes to mind at the moment..
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