Bits I've learned about the 750

[guy2600]

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..

[Waltari]

I'd be interested in seeing the article

[email protected]

[md86]

Freakin SWEET .

[KatMan94]

Is the 600 motor all different or can you do this to the 600 motor also?

[guy2600]

I'd be interested in seeing the article

[email protected]

Done, they're big though (files). So I bought this engine off ebay (94 750), $140. He told me it needed a head gasket cause the radiator was full with oil I tore it apart today, it's MINT! The bores still have a fresh hone and it's the cleanest engine I've split apart. Sometimes you get lucky... I bought a piston kit for it and planned on sending it out to APE for machining but I'm thinking I'll just clean it up and put it back together stock. So how's your gsxr project coming?

Is the 600 motor all different or can you do this to the 600 motor also?

If you mean cams I would guess so but don't know much about the 600's. There's a guy on ebay selling a wesico (sp?) piston kit for a 600 cheap, 645 I beleave..

[damic]

I'd be interested in seeing the article

If you mean cams I would guess so but don't know much about the 600's. There's a guy on ebay selling a wesico (sp?) piston kit for a 600 cheap, 645 I beleave..

Is this "The power of the Poconos" article? It is a good article about a guy who mixed parts from the long and short stroke oil cooled 750. This is not an easy build due to resizing the small end bores of the connecting rods to mate every thing but with excellent results.

If not I would like to see a copy of this article too.
[email protected]

As for the 88 gsxr cams in a 600 it does work because thats what I have.It doesn't increase the low end at all but once up at 7500 the bike takes off. I have a 99 750 motor that needs that needs new rings. Whenever I get around to it I will rebuild the top end and swap engines.

[Court93kat]

I also have GSXR cams in my 600. I used 91-92 750 cams though.

Supposedly the early Kat 600 motors were actually 750 blocks with sleeves in them for the smaller pistons. I don't know the year range for when this started and stopped. A possibility is to use the Wiseco 771 kit for a 91-92 GSXR, as the stroke and wristpin sizes are the same. Have the sleeves removed, and bore 1mm and you will have it.

[guy2600]

I'd be interested in seeing the article

If you mean cams I would guess so but don't know much about the 600's. There's a guy on ebay selling a wesico (sp?) piston kit for a 600 cheap, 645 I beleave..

Is this "The power of the Poconos" article? It is a good article about a guy who mixed parts from the long and short stroke oil cooled 750. This is not an easy build due to resizing the small end bores of the connecting rods to mate every thing but with excellent results.

If not I would like to see a copy of this article too.
[email protected]

As for the 88 gsxr cams in a 600 it does work because thats what I have.It doesn't increase the low end at all but once up at 7500 the bike takes off. I have a 99 750 motor that needs that needs new rings. Whenever I get around to it I will rebuild the top end and swap engines.

That's the article. I'd love to do the build but I can't find a 91/92 bottom end. You can use the 86/87 bottom but the rods aren't as strong. Back when they did the article, the 813 kit didn't exist. I wonder if you slapped an 813 kit with that stroke what the results would be? Someday I'll have to experiment with such things...

I also have GSXR cams in my 600. I used 91-92 750 cams though.

They 600's use a shim head? Hmm.. that kinda sucks. Nice bike by the way...

[damic]

That's the article. I'd love to do the build but I can't find a 91/92 bottom end. You can use the 86/87 bottom but the rods aren't as strong. Back when they did the article, the 813 kit didn't exist. I wonder if you slapped an 813 kit with that stroke what the results would be? Someday I'll have to experiment with such things...

Mr Clean turned me on to a guy from maximum suzuki named fast larry. He did one of these builds and he reccomended shot peening the rods too. He's a good guy so why don't you give him a holler at: http://maximum-suzuki.com
Also many of the guys here frequent there too.

Damic

[kawazymonkey]

I also have GSXR cams in my 600. I used 91-92 750 cams though.

Supposedly the early Kat 600 motors were actually 750 blocks with sleeves in them for the smaller pistons. I don't know the year range for when this started and stopped. A possibility is to use the Wiseco 771 kit for a 91-92 GSXR, as the stroke and wristpin sizes are the same. Have the sleeves removed, and bore 1mm and you will have it.

I have a haynes manual and it does talk about that, saying they were just sleeved down, I'll quote it if you want. But still unsure about the years.

[Special K]

I also have GSXR cams in my 600. I used 91-92 750 cams though.

Supposedly the early Kat 600 motors were actually 750 blocks with sleeves in them for the smaller pistons. I don't know the year range for when this started and stopped. A possibility is to use the Wiseco 771 kit for a 91-92 GSXR, as the stroke and wristpin sizes are the same. Have the sleeves removed, and bore 1mm and you will have it.

Greg:

You're right! The 600 motors are exactly what the 750's are, (cases & blcoks, etc. with the 600's have a thicker piston wall and smaller pistons. Been that way since they began.......1988........still the same! (2006)

Of course, the heads are slightly different, but mostly just the valves and some years or most the cams...............

Trannys are dead alike in a given year 600 to 750, although the clutch packs are stouter for the 750's..............there are a few other minor things internally, but very minor................

[damic]

You're right! The 600 motors are exactly what the 750's are, (cases & blcoks, etc. with the 600's have a thicker piston wall and smaller pistons. Been that way since they began.......1988........still the same! (2006)

Of course, the heads are slightly different, but mostly just the valves and some years or most the cams................

Just a quick question Kieth.

The pistons on ebay that was mentioned earlier in this thread is for 88-91 kat 600. I did a check on bike bandit and they said the pistons for the pre 98 kat were different part numbers. What would be your experience with gen1 & 2 Kat 600 motors when it comes to comparing pistons?

Sorry for the hijak

Damic

[flyguyeddy]

bumping this up to the top.

has anyone actually swapped the cams from intake to exhaust?

i have read about this on SV650's, but NEVER a katana.

[steves]

bumping this up to the top.

has anyone actually swapped the cams from intake to exhaust?

i have read about this on SV650's, but NEVER a katana.

The bandit guys swap GSXR cams into their motors often. I would guess, that on a 750, you could swap cams from an oilcooled 750.

[md86]

It's not swapping the cams from intake to exhaust , it's swapping in one from another bike , and moving ONE of your cams . Just don't remember how that worked ....