Gearbox shot

[Unruled]

Hi guys,

It seems I may have somewhat killed my gearbox the other day. While riding off I opened up quite properly and it seemed to hold back a bit. Therefor, I let go of the throttle and it decided to start crackling and making all sorts of wobbly noises. Not too good, anyway. To sum things up: It won't shift. The gearshifter is quite simply stuck, regardless of what I do with the clutch. If I start the bike, it rattles horribly. If I just push the bike, it still rattles horribly (worse pushing forward than reverse). I've had the front sprocket cover off and my front sprocket is still fixed firmly on the axle. The axle itself however has a new axis of freedom, allowing it to move back (toward the rear wheel) a bit. Not good, again. Some oil is under the bike now, not much but I'm not surpised at that, obviously the axle isn't right, thus allowing for some leakage.

Anyway, while I have some technical knowledge I'm not perfect. I'd like to know how achievable it is for a DIY tinkerer to take out the gearbox and figure out what's what. Do I have to remove the entire engine or can you reach? Is it likely to be just the bearing that's gone awry or is the complete thing totally arsed backwards? If so, I obviously have questions about what course to take... I don't want to sell the bike, I'll fix it somehow. What'll be cheaper? A new gearbox or a complete donor engine? In which case, which GSX-R 1100 engines will fit (obviously )? I've heard the 'regular' ones are pretty much identical, but how about the W version? Does it take a lot of converting or is it still basically the same thing?

Thanks in advance, regardless of what's gonna happen I hope you can help me out :) Should the engine really need replacement I'm obviously going to Top-Gear style turn it into furniture 

[Red01]

Get a manual if you don't have one already (see the downloads section of this site).  Study the transmission section and you can determine if it is in the realm of your abilities.

Should you decide to transplant a GSXR1100 motor, a 1992 or earlier (SACS) will bolt right in.  Not too sure about any of the water pumpers.  I've never heard of anyone doing that swap so I don't know if the mounts are the same or not.  You'd definately have to figure out how to hang the big radiator, which is quite a bit bigger than your oil cooler.  (The SACS GSXR 1100 oil cooler is bigger, too, so I'd try to get that if you go that route.)

[Unruled]

Well I am pretty confident in my abilities, the problem is more the equipment that I have. If I really have to remove the entire engine I'm up for a challenge, so to speak.

I figured the oil cooler would be bigger, and I have indeed seen the radiator on the W, which is huge. But I think I can make that work, the engine mounting points are the bigger problem...


What do you mean by "SACS" by the way?

[Red01]

SACS (Suzuki Advanced Cooling System) is the name Suzuki gave to the Air/Oil cooled engines introduced with the first GSXR's and used in many other Suzuki models (Bandit, Katana/GSX-F, Inazuma/GSX, GS1200SS, etc.) in lesser states of tune.

[Unruled]

Ah, alright. I think that's the way I'm going to do it. The W version seems very appealing, but I've come to the conclusion that it's a bit too difficult. I'll need to fix the radiator obviously, but that I can work out. What worries me more is the watercooling itself, how is it controlled? Simply through the ECU or is the wiring harness way different? How about a thermostat? Is the pump electric? What finally decided that matter was that I'm simply unsure about the engine mounting points, I can't seem to find if it would fit *anywhere*, which very much makes me doubt that it will.

No problems with the wiring harness for the SACS version? I suppose not, if it's functionally the same engine.
About the ECU, I figure that for the SACS 1100 I'll still need to change it, right? I mean, a B12 will only do 10.000rpm and the GSX-R 11.500.

That means I'm left with the problem of finding this particular engine... Seems to be somewhat rare 

[Red01]

Not so much rare, but when they become available, they usually go quickly as the 1100 motor is a popular swap for early GSXR750's, too... in fact, some of the 750 guys even swap in B12 motors because they're easier to come across.

[Unruled]

I was going to have a look into the problem this afternoon, but I ran into a nice offer, 30.000km GSX1100R ('92) engine for 500 euros... Which I bought. I'll be putting that in then :P

[stetracer]

Just my opinion but if your going to do a motor swap I would go with a 89 or 90 gixxer 1100 as it does not have the shim style head or just look for a 91 or 92 gixxer 1100 bottom end and put your top end on it
But if it were me I would just fix it and while i was in there I would replace all the bearings so I knew it woulg be good for many miles. you never really know what your getting when you buy used motors

[Unruled]

Time for a little update :)

I've put in the GSX-R engine and modified a GSX-R CDI to work with it, it runs absolutely fabulous and it's notably more powerful than my already tuned B12 engine. I've also come across a rather unfortunate problem.

The engine jumps from second gear :( Everytime I accelerate, at 4.000rpm it jumps to neutral. Not impossibly to live with, but I want to live without it. Can anyone tell me what it would take to fix this? How far would I have to disassemble the engine, what would it cost?

Thanks...

[Red01]

Could be a bent shift fork.  Never had to tear into my gearbox, so I can't say how involved it would be to replace, but I'm suspecting it's a tear down.