Hey all, it's finally happened!

Yamaha recommends torquing the rear axle nut on the MT-09 to 108 lb-ft, which honestly seems pretty excessive. I’ve always stuck to 100 lb-ft using a proper calibrated torque wrench and I’ve still ended up with some thread wear on the axle and nut. I went to tighten the wheel and I had that horrid feeling of realising it turned to infinity.

From what I’ve seen online over the years and now finally experienced myself, that high torque might be fine the first time with brand-new parts, but it’s not good if you’re adjusting your chain regularly. I think most of us are loosening and tightening the axle fairly often, and that kind of repetitive stress seems to slowly wear things down.

I've learnt from this, as it's completely my own fault still, a 7 year old bike and I've never changed those parts.

What I’m planning on doing now:

Torquing to 95–100 lb-ft max, and that’s only if the threads are clean and in good shape.

Swapping out the axle nut every once a year.

If I use a bit of anti-seize, I will drop the torque a bit more maybe 90–95 lb-ft.

So, when should you replace the Axle?

I've researched this and can't find an actual recommendaion, I guess if the threads are still clean and not damaged, you can probably get years out of it, seems like 7 :)

But if the nut doesn’t go on smoothly or you see any flattening, galling, or metal flecks… it’s probably time to bite the bullet and replace the axle. I’d now going to take it out and check it once a year.

Curious to hear what others are doing with your bike, anyone using Loctite and going lower?

Pure bike porn. New axle and nut at 100 lb-ft.

I put copper slip on my axels. Seems to protect them...

Well, it all went downhill after changing the axle.

Went to start the bike up afterwards, turned over fine, but wouldn’t fire. Cranked plenty, but just no start. I had a feeling it might’ve had some water ingress, as I’d washed it before working on the axle.

Pulled the tank and airbox off, everything looked bone dry. Took the coils off just in case, also completely dry. Put it all back together and tried a few wide-open throttle starts to clear any flooding. Waited a few minutes and tried again normally... pt pt pt bang stop. It almost started.

Hooked up the OBD reader, no stored fault codes.

Then, suddenly: click click click. Wouldn’t even try to crank. Thought maybe the battery was on its way out, so I charged it for a couple of hours, full charge. Still just click click click. Figured maybe the starter fuse had blown. At that point I gave up and booked it in with the local bike shop.

Garage called later. They wanted to know a bit more history, said they weren’t 100% sure what happened, but they got it started using an external battery. No idea why it wouldn't start with me.

But then they asked me something worrying: “Has it been overheating?”

Not that I know of. Then again, I only ride it 30–40 minutes at a time commuting, so if it had a slow overheating issue, maybe I never noticed. They told me the coolant hoses were collapsing, and that with the radiator cap off, coolant shoots out when you rev it.

They compression-tested all three cylinders, all came back fine. So now I'm hoping it's just the head gasket, and not a warped head or cracked block. It's only done 23,000 km, so hoping it’s repairable.

A sad weekend for sure.

Down 2hrs diagnostics so far.

hmm...sounds a worry. please say how you get on - initially seemed an electrical issue and now something to do with the coolant, quite odd really.