People manage to burn up clutches even within several k. Possible someone may have been in it already and just didn't clean off the old gasket material well enough for a good seal with the new one.

These engines keep their oil pretty damned clean; even when they're out of tune and fouling the plugs. Unless someone has been taking things apart and incorrectly reassembling, I doubt the crankcase breather is blocked.

The thick hose running off the back of the air cleaner, almost straight down to the top of the engine is probably the breather hose. Not sure how it's setup internally but can look at the exploded diagrams at 2007 Yamaha YFZ-R6 (YZFR6W) Crankcase | Ron Ayers to see how it's setup. But it just lists the part as a "cover". I'd expect there to be some sort of reed valve there at a minimum, but perhaps it is just open; in which case you can just fish a wire down there to verify that there's no buildup of any kind.

 

Thanks for the reply Intuit.

I have had the bike since 2,000 miles and have never opened the clutch cover so presume the gaskets just gone bad. I will have a look at the breather and change the gasket and see if that fixes it.

cheers

 

So I fitted a new gasket, the leak is still there but a bit worse. I torqued to spec in a star pattern, but the leak seems to be coming from the two bolts at the top and top left. Any ideas on how to fix? Can the bolts be sealed?

 

 

This is after a 20 min ride, the oil seeps and runs down the side of the case

 

Usually that's a surface prep issue. If there's any residue on the surfaces the gasket won't seal. If there are any gouges or scrapes the gasket might not have enough depth to seal. No choice but to use gasket maker on the mating surfaces.

 

So I redid the cover with a new gasket and cleaned the mating surfaces to bare metal. I checked for scrapes and gouges but there weren’t any. The cover still leaks the same through the bolt holes only, nothing where it joins. Should I redo with a new gasket and gasket sealer? Or could I use something in the bolt holes?

I thought it could be a warped case but there are no leaks where it joins.

I’m just lost as to why it’s only leaking through the bolt holes.

Thanks

 

Review this thread.

Clutch cover question

I need to tear into my 2003 r6 clutch. No big deal, but I noticed in the service manual they label needing yamaha bond on a bolt that goes into the clutch cover. I've never seen anyone mention this and out of all the videos I've seen, nobody has done that. My question is how important is it that...

www.r6-forum.com

 

@Shawn855 may have comments.

 

Thanks Intuit.

I had seen about the one bolt which needed the sealer, as I understood the newer gaskets now have an extra bit of gasket sealer already on them so they no longer need it. I haven’t used the sealer on the bolt with the arrow as this has not leaked, but think this would help with the other bolts.

I have some black high temp silicone gasket maker so will try a bit in the bolts that leak.

Cheers

 

You still need the sealer on the bolt(s) specified by the arrows despite using the newer style gasket. The gasket prevents the oil from escaping through the mating surface however on the bolts specified, the oil is able to creep out from behind the bolt(s) because those bolt holes are not enclosed like the rest. So in this case the gasket does nothing to prevent that. Because i'm bored at work, I edited a lovely image to give you an idea as to what i'm talking about.

 

Thanks for the info.

I put sealer on the bolts and it still leaks, seems to be out of the bottom of the cluch cover case seam and the same bolt, also seems to now be weeping out of where the clutch arm comes out of the cover.

I’m back to thinking it could be excessive crankcase pressure pushing oil out of the weakest parts? I will take the tank off and have another look at the breather hoses. Are there any other ways to test this?

cheers

 

Crankcase should vent into the airbox so the emissions can be recycled back into the combustion chambers.

 

Sorry if it's already been mentioned but are you torquing the crankcase bolts to spec? I thought mine were nice and tight until i took my torque wrench and torqued them to the spec required and realized wow, they were still far off.

 

No problem, yes I bought a torque wrench and did them to 12Nm - 8.7ft.lb might recheck them just to make sure.

 

Also everything was fine with the breather, I removed and checked the hose and where it joins. So either I'm not fitting it properly or the cover is cracked/warped

 

If anyone sees this thread with a similar problem it was caused by hairline cracks on the inside of the cover where the bolts screw through (like in the pic above). A new cover fixed the issue