Tenere broken in Toulouse!
 

Hey Folks,

A quick question if I may. I'm on a 2008 Tenere (XT660Z @ 28,000 miles) just ridden down from Edinburgh and having problems with the oil..! I'm not asking for help or a hand out, just an opinion.

It's drinking loads of oil (read: LOTS over 1 litre in 2 days), thin black smoke coming out the back on acceleration and oil filling the airbox drain pipe, which when drained and inspected, there's an odour of petrol and a burnt smell.

It has power and starts fine but I've decided to hang on here in Toulouse and see a Yamaha garage. I'm thinking piston rings..? Or valves....?

Funny though....... if it is the valves, it's just been serviced by Yamaha before I set off specifically asking them to check the valves. The rings I had go on another XT600e and got blue (not black) smoke from the back end whilst drinking oil like a fish. hence the thought on valves.

Any takers on something different? reckon the warranty might cover it here in France? I've definatly missed the HU Andalucia meet and am gutted!

Opinions would be appreciated and lets see if the french agree. (Mais NON Monsieur...... la moto est bon, but your hair is a mess!") LOL

does it put out blue smoke on deceleration? or on startup and accelerating? perhaps does it have an oil leak someplace? granted this would be a significant leak, but still.

how does the spark plug look? rings will just put blue smoke all the time, valve guides will do so if the throttle is opened, then snapped shut creating a strong vacuum, which generally pulls oil from the head. worth looking into.

Sounds like you are overfilling it with the airbox clogged with oil - are you checking the level right as you might just be blowing an excess litre out into the airbox and keeping overfilling it? Presumably you've been moving pretty swiftly too which singles don't like so much if sustained....
Even if the valves were out it would not cause oil consumption.
If any bits were seriously worn, I'd expect poor fuel economy too - how's that?
Any mechanical noise?

General rule is; smoking on power points to rings/bore, smoking on overun(closed throttle) indicates valves/guides. Sounds like rings but I can't think why it's black(unless crankcase pressure is blowing oil into the exhaust through the pollution reducing bumf but I've no idea how all the modern plumbing works) eg black because it's unburnt oil mist rather than the blue of burnt oil. Is there a nipped/blocked breather?

fuel economy
 

Fuel economy sucks..! I do ride it pretty hard averaging 75-80mph and the consumption is since Edinburgh 1787kms/113.96ltrs = 15.68km/ltr...... ouch!

The engine itself is as dry as a bone outside and no leaks and it's supposed to be able to sit at 85mph all day on a motorway.

I'm not noticing blue smoke on deceleration as I'm looking forward but checking the oil level is like other XT's (I've had two), after a warming up run then check. I've been checking all day especially when pulling into the fuel station, which should give me the correct level. So if it shows empty on the dipstick I've been filling it to 1/2 way. I did think it may be over filled as the airbox has oil in it but it shows empty on the stick after a long warm up run of say 20kms...... Aaargh!

I've not had a problem with it before I put it in for a service with Yamaha in Edinburgh, I'm even thinking do I have the right bloody dipstick in it!


The bike seems to run ok when there is absaloutly nothing showing on the dipstick..!!! But the fear of running it dry and melting the engine is driving me nuts, so ........?

Nipped/Blocked breather........ hmm, now where the bugger is that?

Poor fuel economy + oil consumption would seem to point to worn rings; 28,000 is a reasonable mileage for this to occur if the bike has had a hard life and/or not been looked after.

If you are checking the oil right, I'd look at the rings - compression test is pretty easy to do.....

Africa
 

The bike has done UK-ZA before I got it. I'll check the pressure tomorrow if the dealer will look at it, But I am in France..?

I've looked on XT660.com and it appears there's a mod which will explain a lot of oil under high revs for long periods of time, but as with you I'm also going for rings. Hopefully tomorrow we shall see..........

Thanks for the opinions lads, much appreciated and I'll keep you updated with tomorrows adventures at the french Yam shop!

As the fellas before me have mentioned allready its probably piston/rings/cylinder damage due to wear and tear.
A couple of other things to look out for is a blocked air intake/clogged air filter, this will cause the fuel mixture to run very rich, giving you lots of black smoke and it washes oil from the cylinder wall, this will wear out the rings and cylinder/piston thus causing excess oil usage, the worn rings will also allow combustion pressure down past the rings and this pressure will force oil up the breather pipe and into the airbox.
Something else to watch out for is a partially or fully blocked crankcase breather, at high rpm the excessivley high pressure inside the crankcase will force oil up past the rings which will then be burned off in combustion.
Let us know how you get on tommorow.
P.S. looks like im not the only one with mechanical troubles at this late hour, I just got in from rebuilding the gearbox on a 885cc Triumph:sleeping:
Best of luck and if the Yam dealers in Toulouse are half as helpfull as the ones in Rouen then you'll have nothing to worry about.

Piston
 

Yep,
Toulouse yamaha say it's the piston rings and might even need a rebore. He also said it couldn't be done quickly and could take up to a month but guided me to an another bike garage and he's doing it as we speak, should be about a week if a rebore doesn't need doing.

It's not a bad place to be as my hangover proved it this morning..!

Mate, if he is not too far through the job I'd get a re-bore, oversize piston and rings done all at once; the chances of just the rings being knackered are slim - better to do the whole lot as just doing the rings is a short term 'fix'.

new cylinder
 

I've just been given the bad news......... ! Aaargh! The cylinder has gone oval?? New thing to occour to me but apparently so.
The choices were.........

1. Get it rebored, takes a month and then requires an oversized piston, etc.
2. Get a new cylinder from Yamaha, with piston, etc. done by friday.

I've had to go for the expensive option (but quicker) as I have to be in South Africa by the start of October and can't afford the time to be pissing about in the same town or even flying home for the time it takes the bike to repair. At least everything will be new so I'll definitely know everything will be fine once done. Plus Yamaha won't do it under warranty as it's a piston ring problem.

He gave me a price for the cylinder, piston and parts and I'm dreading the credit card taking the hit as my trip is completely shot now!!

Och well, back to the pub for another few pints of tear drowner!!

your cylinder has worn out of round? how the hell? I've heard of this with POS kawi bikes, particularly the EX500, but not on a yamaha.

Sorry to hear that.
It is sometimes caused by uneven wear on the cylinder and the causes are usually not changing the oil, those mentioned by Adrian74 above and poor quality engineering.
Given the history of your bike, the trip to Africa and back likely took it's toll and if the maintenance was poor or non-existent, there's your answer.
The 2008 and on KLR 650s have a similar problem and this has been put down to crappy engineering from Kawasaki.
Not heard about it on Yamahas though.
I'd have done the same given the choices you had.

Bigbore thumpers with lots of miles/km on 'em get oval at some point, period.

Its pretty natural when you think about it.

My buddys '92 xtz660 did it at around 80.000km.

My xt600e still goes strong at that odometer reading, but i know it will happen at some point. Just a chance to get more ccm's and more compression :D


But it does sound early for you're bike. But noting to do about it now. Sounds crazy that it will take a month to get it bored and honed. Its not even an hours work. How much is a new cylinder and piston?

est of luck mate and keep drinking...beerchug