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Gearbox ID.


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Posted

Can anyone ID this gearbox? I know they all look the same, so I've put the selector drum in the frame too. It's a bit different to the 1100's I'm familiar with. I've a sneaking suspicion it's GS750/850? 

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Posted
2 hours ago, wraith said:

Not GS850 as it has a sprocket, - correct - and (if I remember right) the GS750 had straight cut gears. - Correct again but straight cut primaries so doesn't help here?

Are we knowing if was air cooled? The input shaft at the clutch end is weird looking!

  • Like 1
Posted
16 minutes ago, Gixer1460 said:

 The input shaft at the clutch end is weird looking!

Correct. Typical fine spline blonda with machined grooves on bearing area. Also shift drum is typical cbr. Fleabay has a few under cbr600. 

Posted (edited)

This is getting really interesting! The motor came out of a supposedly 1150 EFE, but as soon as I clapped eyes on it, I knew it wasn't!  It's frame number started DV, where EFE's should start GV (or the other way round)? No engine numbers either!  It was even documented in the V5 as, 'Engine number: Not known'. Never seen that before!  It was fitted with 998cc barrels. I forgot about 850's being shafties, so they're ruled out! The fact that it's a six speed ... how about any of the smaller GS's? Were they six speed? Would a twins gearbox even fit into a four? What about a 550 EFE? Same type of square section frame. What did their frame numbers start with? I'll dig the photo of the gearbox's original home out later on. By gum, 't things caused reet aggro!:D

Edited by Swiss Toni
Missing text.
  • Like 1
Posted

This is the cluster fitted to '78 GS750EC cases. As you can see, the case isn't wide enough, and the housings for two of the bearings are far bigger. So, the original engine wasn't GS750! Well, I'm saying wasn't, as in 8 valve 750! The donor was 16 valve. 

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Posted

Fitted to GSX1100 cases. Same problem. Cases not wide enough, two housings too big. I'm really starting to think smaller GS. But, would crank & barrels transplant? I know the crank is definitely 1100, as I've measured the stroke at 66mm, and small ends are  18mm. And, as an aside, how do I insert text between pictures, using iPhone? Answers on a postcard please (PM me)!

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Posted

Well a GSX1400 ticks all the boxes - stroke should be 68mm, its a 4v and it is a 6 speed! And looking at the parts fiche the input shaft does look different - like the above, but hard to tell !

Posted (edited)

@Gixer1460Yes, twas an Aircooled! 

Well ... '83 GSX 550ES is also 6 speed, but stroke comes out  @ 50.6mm. And 16 valve, as you'll see the donor motor was.  GS 400 twin 6 speed, but stroke @ 56.6mmm. Picture to follow because,  'We like'  ... 

I know, I know! :)

Edited by Swiss Toni
More info!
Posted (edited)

Pictures show the GS(X) motor the gearbox came from. Fitted with 998cc barrels, 16 valve head, can't remember what the carb sizes were. So! The mystery continues! What interests me is, what the crankcases were,  to be able to take 1000/1100 crank, head & barrels? GS1000 perhaps, or 16 valve GS750? Essentially, a six speed GSX, retro fitted. I never rode the bike. It was stripped as the frame was cattled! 

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Edited by Swiss Toni
Posted
On 11/8/2018 at 11:19 AM, Swiss Toni said:

Can anyone ID this gearbox? I know they all look the same, so I've put the selector drum in the frame too. It's a bit different to the 1100's I'm familiar with. I've a sneaking suspicion it's GS750/850? 

image.jpg

It's a 6 speed, so not an old GS

Posted

Fancy one-off six speed gearbox for road racing? What became of the dodgy numberless cases? Dunlop's 'xr69' has an engine with no number on it. I did see this at a bike show.

Posted (edited)

Those are 16V cases ...as to fit 16V block and Head on 8V cases means Major work

Liberty and Vance and Grimes both do a 6 speed for the 16v cases "Read v expensive"

if you have as the pic tried the box in GSX 1100 "16V" cases and it don't fit as your pic shows

have you considered the idea that its not the box that came out of the motor in the quoted pic above

and you have mixed it up with another 6 speed box..........

 

Edited by Duckndive
  • Like 1
Posted
3 hours ago, Dezza said:

Fancy one-off six speed gearbox for road racing? What became of the dodgy numberless cases? Dunlop's 'xr69' has an engine with no number on it. I did see this at a bike show.

I sold them to a drag racer on the old site, years ago. Bought 1100 cases from a lad on the old site, who ran a business for Malt Whisky.

 

1 hour ago, Duckndive said:

 

if you have as the pic tried the box in GSX 1100 "16V" cases and it don't fit as your pic shows

have you considered the idea that its not the box that came out of the motor in the quoted pic above

and you have mixed it up with another 6 speed box..........

 

Yes, it's definitely  the box from the last pics I put up. The only other 6 speed box I've had lying around, is now safely back in the Slabbie.

 

...... I think! :D

 

 

 

......................... I hope!!!!   :S

Posted
1 hour ago, jameskat said:

After looking at photos online it does look very much like a CBR900 gearbox, does not look like a hayabusa or gsx1400.

Seeing how wide it is now against the 750 cases as 1100/1150 cases are not much wider. I suspect it is blackbird 1100xx. 

Posted

Perhaps looking for markings would help ID-ing it as a H*nd* box. If no partno.'s are stamped om gears or shafts, at least the sprocket will be stamped by the aftermarket(?) factory. Beside looking up that number also the spline dimensions on the output shaft should help with determining the identity of the gearbox.

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