Stripper.

[DaddyStu]

Had an annoying strip of the sump thread today. At 25Nm versus a stated 43 Nm spec.

Stripped 3 rotations of thread. Found a longer bolt to utilise the remaining thread and torqued to 20Nm. All ok but still a bit of a nuisance.
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Daddystu
Zontes 125-G1 (part-ex'd). Yamaha Tracer 700.

[Nobby the Bastard]

43 nm is a hell of a lot for a sump plug.
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[sickpup]

Lots on the internet suggesting that this is too high and Yamaha have potentially revised the torque setting.

You may have a case against Yamaha, they have paid for some peoples repairs.

I have had the same problem with Kawasaki.
Front sprocket nut torque setting on the ER-6 2008 is a whooping 125nm with a lock washer on a fine thread which is ridiculously high. High to the point that the engine in gear, the rear brake held on with someone on the bike, the sprocket still turns and the bike moves yet Kawasaki insist it is right. To get the sprocket off I had to put a breaker bar through the rear wheel, a piece of 2x2 was ripped apart.

[Nobby the Bastard]

[sickpup]

Why a front sprocket with a knock over tab, lock washer needs that kind of torque I have no idea.

Just to be clear, I'm not blaming the OP in any way. There are lots of odd torque settings that don't seem to make any sense yet the manufacturers insist they are correct right up until they have to pay for the damages.

I did discuss the front sprocket torque setting with Kawasaki tech who initially wanted me to refer it to a dealer (yeah right) and then just said if its in the manual it must be correct.

[Nobby the Bastard]

I can understand something holding something oon having to be tight but a sump nut doesn't need to hold anything on, it just needs to make a seal.
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[stinkwheel]

Mind you, isn't a sump plug M12 x 1.5?

42Nm seems a reasonable setting for a bolt that pitch going into aluminium based on the few spec charts I can find. HOWEVER, those are based on at least 20mm of thread engagement and I wonder if you had this. They are also based on a fastener being put in once. Aluminium galls, the more often it's disassembled and re-assembled, the more it galls.

That said, industry standard with oddball dissimilar metal applications is to make multiple examples of the application in question, find the failure point then make the standard tightening 65% of the average failure.

I have said it repeatedly, I can't understand why they don't use bonded seal/dowty washers on sump bolts routinely. I'd recommend them to anyone, if it feels tight enough, it's going to seal.

With regard to the sprocket nuts, I wish they'd give over using them on motorbikes. A concentric nut on a rapidly rotating shaft is silly, although in terms of tightening, standard torque for a high tensile M20 fine is actually 460Nm. It's a failure point in any case, precession is the enemy and a tab washer hardly seems adequate, hence the ludicrously beefy nuts for something that sees almost no lateral force. They used to be held on with offset spline washers bolted to the sprocket, perfectly adequate and a small amount of float on the splines isn't going to do any harm.

Even the old Brit bikes used a more sensible system, they had a central nut then a locking screw was put into the face of the sprocket so its head engaged on the flat of the nut. You can do up the nut kind of tight-ish, it's the screw that ultimately holds everything in place, if it's in, the nut can't undo.

In any case, using a torque wrench is not a substitute for paying attention.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[DaddyStu]

[stinkwheel]

You could always stick a small disc magnet to the oil filter if you want that belt and braces. Although to be fair, do you ever find anything stuck to the sump plug one?

Even my pre-unit enfield which has a huge magnet in the oil filter housing doesn't really ever have anything on it. I think sump magnets are a relic back to when vehicles didn't really have oil filters. If you're getting ferrous metal particles flying round the engine of a modern japanese motorbike, all your magnet is going to do is tell you your engine is already fucked. The filter isn't going to let anything over 40 microns through to any plain bearings anyway. All the magnet's going to catch are things the filter would have caught anyway or big lumps that have fallen off your transmission.

On balance, I'd suggest all a sump bolt magnet is going to do on a modern bike is be something that could potentially come adrift and get minced by the gearbox, spreading highly magnetic dust all over the transmission and charging system.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Easy-X]

"Ooooo! Magnetic sump plugs, sounds like a great idea!" my reaction initially

On an oil change they just seem to have a metallic sludge, the sort of stuff that was probably quite happy to be suspended in the oil and doing little harm. I suppose if you found some actual swarf or shards stuck to it you can go "oh noes! something up wiv me engine!" but then surely you notice something when "panning for gold" with the drained oil.
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[DaddyStu]