Hi from a newbie and a question - srx gearbox

[guest1670]

Hi all.

New to the forum and think I probably posted this in the wrong section, so trying here!

Been meaning to join for a while, having bought a srx600 back in February. It's been under a cover up until now, whilst I made room in the garage in between working on my other projects. I belong to several other forums, always find them invaluable and have been known to offer a few useful snippets myself too!

Anyhoo, here goes for the first of what will probably be many questions, as I'm doing a ground-up rebuild. I have an '87 1XL, engine stripped, shopping list ready. Main problem is the gearbox which is more or less b*gg*r*d. I was expecting to find some wear on fifth, having read a lot about this being a common problem first, but 3rd and 4th are both badly pitted and shot, 2nd's not too healthy either, making me wonder if the old girl has been raced somewhere in it's 56K mile history. At a minimum then I'm looking at a pair for 2nd, a pair for 3rd, a pair for 4th and ideally a 5th too! I don't mind buying the odd part from Mr Yamaha, but this lot doesn't come cheap and it's only the start!

Anyone got any usable gears or maybe a complete gearbox they could sell me? Recommend a breaker? Know of anything compatible? I could feasibly just put it all back together as is and give the problem to someone else, but that's not my style and to be honest I bought the srx cos i love the look of them - it's meant to be a keeper.

Cheers
Martin

[SRXweb]

Hello and welcome.

Note sure I understood everything but do you mean to put second hand gears ??

I think you can find on Kedo website more affordable gears than in your local Yamaha dealer.

[themoudie]

Aye Martin,
Welcome to the loony bin, I hope you are able to find a well worn leather chair with a wee dram to suit you. 

So far, with 85K km on the clock, 'Sally' (SRX600) hasn't required a load of gears. Only required renewal of 5th pair when stripped for other reasons at about 50K km. I bought Yamaha gears from the dealer, as the hardening and tempering was supposedly improved from that carried out on the early 1JK motors. I don't have any spares that might be of use to you at present, I am afraid.

However, SteveH, SteveL and Ian maybe along soon to offer opinion and advice, or even a spare or two.

However, in the mean time as SRXweb suggests, have a look at the KEDO catalogue (you can translate some of it and they speak English) here: KEDO  Page 125 of the catalogue is the initial 'interest' for the gears, but the rest is well filled with reputable bits! 

Hope this helps.

My regards, Bill.

[guest1670]

Thankyou kindly folks, for a steer in the right direction. I'll do as you suggest and check out Kedo tomorrow - need my ugly sleep now. Please chime in though anyone who has any decent used parts to sell.

I'd love to know the history of this bike, been delving into bike engines for the last thirty years or so and have rarely seen so much wear. Top end looks like it's been apart before though with the liner still within spec. It had a huge black fairing attached when I bought it, which upon reflection may have been a clue to a PO with racing aspirations? Then again could just as easily been some old duffer like me trying to keep his flannels dry.

I'll post up a piccy or two when I work out how to do it.

[themoudie]

Aye Martin,

Are you alright for a workshop manual? If you would supply your email address to to my PM on the lefthand side of the message, I'll arrange for a *.pdf to arrive!

This is an aside for another affecianado! Andy230! One of yours? 

They like clean oil Martin and don't like to be 'lugged' in the gears, that's the cause of the wear in the gearbox a lot of the time.

All the best, Bill.

[guest1670]

PM sent!

[Steve H]

I believe that one of the XT600 parts suppliers in the UK can supply a beefed up 5th gear. I believe the company advertised in TBM (Trail Bike Magazine)
I would recommend buying new gears, anything second hand is either going to be knackered or on its way out.
I have heard lots of theories as to why they fail, all I know is that of the five or so engines I have stripped all have had duff gears in the gearbox, if they are left then the debris from the failing gears will take out the oil pump as well.

[guest1670]

Sounds like sound advice to me Steve, thanks.

[themoudie]

Aye Martin,

I you have a 'Search' of the site, using the button top right of the screen, you'll find a conversation some years ago about buying and or refurbishing said oil pump. Will dig out if 'Search' doesn't.

My regards, Bill.

[Steve Lake]

Hi Martin... welcome to the nuthouse... amongst all the complete bol*ocks written on TC pages. ... you'll find some real gems relating to the SRX, there are some very knowledgeable guys in here (somewhere)....

now... I have 4 or 5 part or nearly whole SRX 400 lumps... the gearbox internals are virtually identical (just different ratios)... and the difference can be adjusted for by changes to the gearbox and rear sprocket.... i'm happy to flog you the bits.... (no work...no fee...except carriage)... but as has been said many times here.... it is better to buy new if you can... (having said that ... i'm the exception that proves the rule..... of the 7 SRX6's I've owned/rebuilt   ... never had a gearbox problem)

with regard to oil pumps... yes the seals can fail... and no.... they are not available from Mr Yamaha... and somewhere on here there are details on  how to machine out the seats in the pump and fit seals from a different source (ktm?) BUT.... on every pump I've looked at... yes the seals have been less than perfect (go hard and brittle in the heat, what a wonderful design flaw!) but they are also scored.... just one score mark and the efficiency of the pump I ruined... and your expensive and time consuming rebuild will go bang (especially if you've done a rebore and new piston.... it'll seize... and usually in the same area.... adjacent to the cam chain tensioner)

My bit of holy grail is.... ALWAYS change the oil pump after a major rebuild (ok its the thick end of 100 quid, but it will be an uprated unit now)... and do an oil/filter change regularly (very regularly) and fit a magnetic oil tank plug (ebay)

(and yes.... after my first rebuild the engine did seize... and no... I didn't replace the pump...  )

good luck with the project

[Steve H]

Thinking about it the 400 engine is much smoother and needs to be spun to make progress, as such the gearbox may well be within its design limits in the 400.

[guest1670]

Thanks fellas, lots of good info to chew over. Hadn't  factored for a new oil pump, I'll check out the old threads as suggested first before I take the plunge.

The theory I'm working on is that 5th has been changed before, as surprisingly - that is, contradicting everything I've read, it is by far the best condition gear in the box. I've also come across another little giveaway that it's possibly been apart before as the oil strainer looks as if someone has attempted to prise it apart, presumably to clean it (can this be done by the way? Another £40 saved if it can).

Steve, I'm very interested in your comments regarding the srx400 bits, if I swapped out 2nd and third gears (the worst ones) how would it affect the bike? Or would it be better to replace them all and then, as you say, take up the difference on the final drive?

Still thinking about options, in my heart I know I should really go for new parts and that's probably the way I'll go at the end of the day. Trouble is, I've got a couple more bikes in need of surgery and it's all about the dosh at the moment. Thankfully I don't have a joint account with the missus but if the washing machine were to blow up I could face some awkward questions.....

[Steve Lake]

If you were to use the 400 gear internals I would suggest that you change the lot.... as they may not...individually, mate properly with the 600 gears.

the solution to the washing machine syndrome is relatively simple...   you put a suitable logo on the machine... to match whatever project is going on in the workshop... i.e.......   Norton/Yamaha/bsa/triumph....

then.... when the inevitable questions arise ... like... 'what are all these Yamaha/Norton/bsa...etc...parts for?'   you point innocently to the washing machine... and shrug...

pip pip