A word of wisdom from Larry Cole regarding replacing the Bandit engine:
Anders, I put a 90 Katana 1127cc motor in my 97 Bandit. I'll try and tell you the differences between them. First off the 89-93 Katana 1100's and the 89-92 GSXR's are basicly the same motor as the Bandit 1200's. The Cams are the same in all the above mentioned, except the Bandit. The oil pan and valve cover is different on the Bandit. The clutch is the same as the GSXR's, but not the Katana. The GSXR uses diaphram springs and the Katana uses 5 springs. The Sprockets on the motor are all the same. Ign. advancers are interchangable, and work on the Bandit. You already know about the cam tower, and thats the reason the valve cover is different. The 86-88 are 1054cc motors with a different stroke. If you put the Bandit crank in a earlier motor and bore you can get 1127cc. So stay with the 89-93 Kats and 89-92 gsxr's and your practicly the same motor. Tha Katana has a different final output ratio than the GSXR, thats why they use different gear ratios. Thats about all I can think of right now, hope this helps a little.
Anders, the B12 clutch is totally different , no you cant use the '87-88 clutch because its a 1052cc motor and has more teeth on it, the 1127cc or '89-92 clutch may fit i havnt tried it , larry may have though. IMHO a lockup is a waste of money here, i know of 200+hp motors of this type that dont use one, you have no doubt seen them too even if you didnt know it. one guy in particular runs the lockup spacer plate , but not the lockup !! i'm sure i'll forget something but the major diffs as i recall are the cam chain, crankshaft ( because of the cam chain type) cam sprockets, the cams of course. the whole clutch is different ( havnt checked but i suspect the transmission shaft its on is too) , some early R's used a dual pickup ignition so its not a direct bolt in anyway. as far as fit any 750-1100 air cooled advancer will bolt on but not nessesarilly work well. the valve cover has several variations over the years. dont know for sure but i think the cylinder block is a different casting. the oil pan and pickup are different.
Anders, The only thing I had to do to put the Kat into the Bandit was change the oil pan, valve cover, a couple of bolt on wires, so the harness matched up. No electrical probems at all, its really a easy process. You can check out my web pages for some more info. I also put a 600 Kat motor back into the 1100 Katana that I removed the motor from for the Bandit. This also went fairly easy, just a few slight mods. The exhausts bolted right up on both motors. Larry
Some excerpts from dragbike.com regarding swap'ability of motor cases:
Scott Horner, Sunday, December 10, 2000 - 03:33 am
Cody, The slingshot and Katana 750 cases will work(I have not tried the Katana yet). If you run the 1052 crank you only need to slightly modify the cases for the primary gear and #3 rod. If you run a 1127 crank you need to clearance the cases more for the larger 1127 primary gear (no problem) and the # 3 rod ( watch not to get into the oil galley). If you plan to run Carrillo's, I usually remove the material behind the # 3 rod, it is an oil galley to the tranny input shaft. I will machine the case until I am 2/3rds of the way through the galley. I then weld the oil galley shut and drill the galley at a slightly lower angle into the large oil galley that feeds the mains. I then go back and machine the cases for the # 3 rod clearance. If runnig Carrillo's get a bolt with the short head. A 1052 cylinder will drop right in the 750 cases. For a 1127 cylinder, the cases need to be bored aprox. 1mm. I have run big blocks in the 750 cases without a problem. Like Jay said, you will need to run the small starter. New, the 1052 cranks are $50+ more than the 1127, about $855 good guy price
Alan Herriman, Sunday, December 24, 2000 - 07:40 pm
you can run a 1052 crank & rods in 88&89 750 cases, even use 750 6sd box. didn't have to modify cases, fit 1052 clutch & change gearing to suit, (42/15 used on mine),3800rpm/100kph.with a good head,(108cfm/.350), 36mm cv carbs. only used for street use, but never had trouble with 750 box, pulled into top at 270kph. not many roads around where i live to leg out top gear