Has anyone come accross this and do you think his priceing is true? Its turning into a real money pit!!!
Grahame
Thought my diff was on its way out as I kept losing drive intermitanly for a split second, so decided to replace my 3.62 lsd for a new one! Job
done!! No! Took it out for a blast and stil the same so asked my mate about it as he is a keen biker who stunts and generally puts his bike through
hell (by the way car is powered by a blade RR2 engine). He reckons ive bent my seletor forks in the box and its jumping out of gear then back in, and
went on to say ive probably knacked some of the gears and will have to replace them at a cost of at least £75 per gear!!!
Has anyone come accross this and do you think his priceing is true? Its turning into a real money pit!!!
Grahame
I had this on my R1. Yamaha parts may be different. 3 gears, 1 selector fork and a set of bottom end gaskets. I was charged £150 for parts by the
guy who fixed it. That would be parts only without mark up.
From memory, the plain gears were about £20 each and the one with the selector fork groove and dogs was more like £50.
My selector fork was so bent that it had started grinding against the 6th gear wheel. The dogs on 6th and the slots on 2nd had worn round.
Just pull it out and pop in a zetec instead....you'll benefit from more torque as well! Now, then how long till Hellfire turns up.... 
quote:
Originally posted by oliwb
Just pull it out and pop in a zetec instead....you'll benefit from more torque as well! Now, then how long till Hellfire turns up....
It's not uncommon due to cack-footed gear changes. Selector forks get bent which then cause dogs not to engage properly, and then the damage
spirals....
There is no need to be brutal with a bike gearbox as the smoother you are the better they perform!
The prices you have for gears probably aren't too far out (Suzuki TL1000 gears are around £60 a piece), though a search on eSkip may find you a
complete cluster for the cost of one gear.... 
On the plus side......
Does this mean you now have an LSD diff going cheap?
It's not 2nd gear is it Grahame by any chance? Have a word with Paul Fisher, he may possibly have some spare gearbox bits.
Phil
Yes I do have a spare diff but not selling it just yet unless someone comes up with an irresistable offer
Phil it seems to occur in a few gears, why second particularly? I would have thought Pauls gears are different in the RRY compared to my RR2!
On closer inspection I have noticed that the MK gear linkage that transfers the change from the gear changer down the bulkhead (you know the rotating
spindle in tube) to the bikes selector is loose, therefore creating a loss in actual movement at the gear selector. Of course this can be easily
remedied but the question is has the damage already been done? I think maybe 
Grahame
Grahame, it's usually second gear on a BEC that takes the most hammer and it is usually the first one to go on Blade engines. I think the RRY to
RR3 gearboxes are the same.
The damage has already been done, so it looks like a repair over the winter may be required.
Phil
Further to the saga of the crunching gears, I have got a complete second hand gearbox now so can fix the crunching situation, but whilst looking for
the gearbox on fleabay I contacted a guy who was selling a complete 929 box. He went on to say that nearlly all blade and R1 boxes are flawed and
generally not up to the job of tranmitting the power to the tarmac in a bec!! He went on to say that he knew of a guy who went through three boxes in
a summer! Now, further to this he said the only way forward is to fit a close ratio race box (£600), of which he could supply!! Well, i'm not a
total sceptic and I want to give him the benefit of the doubt so I just would like to know how many of you bec owners who have blade or r1 power had
to replce a gearbox dog, fork etc? Plus have you then gone on to fit the racing box? Will be interesting to find out!!
Further to the saga of the crunching gears, I have got a complete second hand gearbox now so can fix the crunching situation, but whilst looking for
the gearbox on fleabay I contacted a guy who was selling a complete 929 box. He went on to say that nearlly all blade and R1 boxes are flawed and
generally not up to the job of tranmitting the power to the tarmac in a bec!! He went on to say that he knew of a guy who went through three boxes in
a summer! Now, further to this he said the only way forward is to fit a close ratio race box (£600), of which he could supply!! Well, i'm not a
total sceptic and I want to give him the benefit of the doubt so I just would like to know how many of you bec owners who have blade or r1 power had
to replce a gearbox dog, fork etc? Plus have you then gone on to fit the racing box? Will be interesting to find out!!
me. R1. 2nd gear. The guy at the shop said that it had to be done by a foot as a hand shifter in a car couldn't do that much damage.
thrashed mine to within an inch of its life never missed a beat
2nd gear is definatley the weak link in the gear box.
My R1 had a very similar problem to yours and I also thought it was the diff.
It would briefly jump out of second gear into neutral when at full power on hard acceleration about 10,000 rpm. It turned out to be worn dogs on the
second gear which is a common R1 problem. New gears sorted the problem.
Do you use the clutch when changing from 1st to 2nd?
Yes thats exactly whats happening, jumping out into neutral and missing in other gears too, think its seriously crunched in there. Regarding using
the clutch from 1st to second, yes always, although it was always a massive 'clunk', but from second up tp 6th never used clutch!
So i take it the close ratio racing box isn't worth it then Chris? IYHO
It is difficult to know what to do when changing from 1st to 2nd.
I can change from 2nd all the way to 6th without clutch at any rpm and it just snicks into gear.
regarding 1st to 2nd the only sure fire way of avoiding the "clunk" when changing from first to second is either:
1: push in clutch, wait for about 3seconds or so with the clutch in, then change up.
Not very good for buzzing up through the box though.
2: hard acceleration in 1st up to the redline, slight lift off the throttle and quick change up into second, o.k. for track use but not very practical
on the road.
Assuming that the dogs on your gears aren't knackered and you can find someone to do it (or have the time and skill yourself), you can get the
dogs machined so they are undercut with a slight taper on them to prevent them jumping out of gear. Not sure how much it would cost to get them done
professionally, although you can bet it aint cheap.
Just another option worth considering.
Phil
Saw this on my firend's Yamaha YZF600 bike... he was popping 2nd gear due to worn dogs, which bent the shift fork. Parts cost him £130 and we spent a week between classes to split the case and get it back together. Deffinitely a rich educational experience, though.
Thanks for the tips guys, I think i'll rebuild with the full gearbox ive aquired. Although its not new its worth a punt!
Hi all can you tell me out of interest is it just honda and yamaha gear boxes that have this kind of problems . How do kawasaki boxes compare? good or
bad
Jacko
Why do you want to know........?? 
Phil
Hi Phil i see a lots of ppl have trouble with bike gear boxes and just out of interest thats all Graham
No direct experience of Kwackers but I have to say that Suzuki gearboxes live up to their reputation if my old GSX was anything to go by - went from
that onto a CBR 600 and the clunkiness of the Honda boxes was abit disappointing given that it was a more modern machine with less miles.......
Any busa powered car owners like to comment?