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Thanks for the more specific info. I have a 1989/90 3AJ, which is going to Maroc / Algeria / Tunisia / Libya / Egypt / Jordan / Syria / eastern Europe in June next year.
Since 2nd and 3rd were jumping, I was banking on new selector drum and forks, plus new sprockets. The bike doesn't make any wierd noises in any gear, but it has covered 35K miles. At the moment I am changing oil every 1000 miles and nursing the gearbox. I think I should bank on a full rebuild with a top end decoke and new valve seat, rings, etc., and a full 'box/clutch rebuild. Currently I am saving up for this. (!!) It seems that lots of mechanics will quote on a job like this without even having done one before. DL - I will give you a ring to try and arrange a visit soon. Would you be able to have a look / listen / ride? I am in London... |
Personally I opened the cases of 2 2KF and one 34L each of them with *at least* 40.000 kms (used bikes ..don't count on tachos ! one of the 2KF was at last rebore with tacho showing "37.000" kms ....) and none showed pitted or damaged gears ...true is that I always used a lower ratio respect the original (1 teeth less on pinion or 2 teeths more on sprocket) even on my TT heavily used for enduro gears were OK ...may the point is to put the stress on the chain ? (easily serviceable/changeable)
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Hi David Lomax.
Most 1VJs would have had a rebuild by now, so it is always difficult to tell how many miles a set of gears have actually done. I forgot to mention yesterday that it is possible to visually inspect most of the gear wheels with only the top end and piston removed. As you look into the case from the front 5th is the pair second in from the RHS. (As you look at the gears from L to R they are in this order 1-4-3-5-2) The droning noise is not always obvious in the early stages unless you are familiar with it, so a visual inspection is really the only sure-fire way to be certain. I have heard (but never seen) reports of engines with quite high mileages having perfect gears, but unless you can be certain that an engine has never been apart and is not on a replacement set, I think it would be unwise to consider these exceptions as the rule. If the gears were good on the 1VJ then why have Yamaha modified it at least three times since??? If actually splitting the cases then you should also check the guide grooves on the selector drum, they can wear badly on the ramps and peaks causing poor engagement of the gear dogs. The forks and dogs start to wear and the machine jumps out of gear. David L. |
Hi POB/London
No problem, come down and i will have a ride and listen. You mention being surprised that mechanics will quote on this work without previous experience. From their angle this is fair enough as the XT6 is a fairly simple engine, but, the problem is it suffers from a multitude of faults that can never be rectified with a straightforward by-the-book rebuild using std off the shelf parts. A good engine builder will certainly do a good job of building the engine but without the right mods will it stand up to the demands of a long overland trip where regular maintainance is maybe, for whatever reason, not at the top of your list of priorities? Long distance touring is always a bit of a gamble unless you can afford a fully equipped support truck!!! Maybe see you soon. David L. |
David Lambeth
Many thanks for taking the time to reply in so much detail. It seems as if you're the guy I should have seen to get the bike sorted!! May well meet you soon!! Dave Lomax |
Quote:
I don't think my trip is *that* extreme, but I see what you're saying. At the moment my problem is that I can't really afford major work, yet I DEFINITELY can't afford to fix it if it goes pop. A tough one. I have also acquired a pair of 3AJ wheels (rear rim cracked, but both hubs AOK) and a shock / swingarm assembly. Perhaps I'll lash them to the bike when I come to see you... Once again, thanks very much. PS > I crashed my 3AJ the other day at about 25mph, and she slid down the road, sparking. I was wearing my Rukka / Tuareg gear so I was fine, and the damage to the bike? 1 filed down brushguard and a cracked indicator lens. These are tough bikes! (apart from 5th...)_ |
Sorry to bring this old chestnut up *again*, but does the following text (from the very good "Tenere History" page) mean that 5th gear in my 3AJ may be good for some time yet? Were the mods by Yamaha sufficient? Or should I still try and get at least a gearbox rebuild before my trip?
"Also the cooling fin surface area was increased by one third. In addition, the lubrication circuit was optimised and fifth gear was strengthened. Thus the Ténéré again became a reliable long-distance touring companion." What do you think? |
I had similar problems with my '86 SRX6 which has the same (or very similar) engine as the XT/TT. When I bought the bike it never seemed happy in 5th on a motorway, however as I'd never had a single before I put it down to the engine. I did 10k kms with noticable vibration in 5th, and only then did the remaining teeth finally give way.
Interestingly, I could only find three of the four missing teeth in the crankcase. Also, one of the tooth 'stubs' on the gear looked very different to the others. I can only conclude that the not-so-mysterious vibration I had expereinced in 5th was due to a missing tooth. There was no damage to the rest of the engine as a result of the initial tooth disappearing (probably fished out by the previous owner) or the subsequent teeth. The good news is that, in one case anyway, the engine can survive losing a few teeth. Maybe I got lucky? B |
Hi
Seems like you were very lucky. My 3AJ was only missing small pieces from its 5th gear (no whole teeth) but to my surprise it completely ruined the oilpump. And the oilpump is much more expensive than the new fifth gear :-( I just now heared that the XTZ660 oilpump also fits on the XT600 and has much more power. This should help to keep the 5th gear in one piece. Peter |
So if I were to fit a new XTZ660 oilpump to my 3AJ it could prevent the problem? Or stop it from getting worse? Anything to help would be great!
PS > discovered today that my sponsors are paying for a custom rear shock rebuild (based on rear axle load weight??). Yay! |
Hi again
The 660 oil pump that everyone is talking about is a 3AJ unit. The only way to avoid the gear problem is to uprate the gears or fit a 96 onwards XT motor. (no the 96 gears dont fit straight into any of the earlier engines) I have sold many many of the uprated kits and to date have never had any reports of problems - when I do I will let you all know so we all have an idea of how long the kits can be expected to last. David Lambeth. [This message has been edited by david lambeth (edited 15 December 2002).] |
Dave,
I have a 34L Tenere. It has an genuine 50000km on it(got it from the original owner!). Does the above discussion about 5th gear apply to this model as well and if so is the remedy the same? Thanks, Brian ------------------ |
I just opened my 3aj. It has 22000km on the clock. 5th gear on the primary shaft is badly pitted, also the 3rd gear engaging dog is badly damaged with a chunk missing.
These gear boxes are very easy to open up, so its no problem to have a look if you suspect problems. |
i ride the xtz 660 4my, does this bike have the upgraded gear boxes, i am planning a rtw trip on this bike and hope its gear box can survive.
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Hi,
dont worry, your XTZ 660 has endurable gearbox, much better than mentioned old Teneres. My gearbox is perfect after more than 100.000 km ! AnteK |
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