Hi guys, I'm new to this forum, I was a regular on Ducatisti. I've got a major problem, after a keen down shift, my 600SS developed one hell of a loud clatter. as shown in the video below. Death of a 600SuperSport - YouTube The bike seemingly ran fine but with the loud metallic banging, it got me home alight, and there's no smoke emitting from the exhaust. I suspect therefore the problem is bottom end, possibly big end bearing? Anyone had a similar issue? is it cost effective to strip, machine and fit bigger bearings? Any help/advise welcome. Kind regards, Jacques Wood
Doesn't sound like a big end to me, they are quite robust, and so long as there's clean oil, at the right pressure, they tend to last a long time, but I've no direct experience of the 600 flavour ss. Sounds more like a top endy sort of noise to me, but till you get the lump out of the frame and in bits, its tough to call. Probably best to start by pulling the plugs, and seeing if there's any debris in the combustion chambers, see if the belt has jumped a tooth or several, and take the inspection covers off the heads to see if you have dropped a valve.
What he said. Or just ride it as is? A lot of wet clutch owners spend a lot of money getting that dry clutch sound?
Sounds like exhaust to me . Check your system for cracks or maybe the gasket between the exhaust and the engine or one of the joints.
Is it still firing on two? (its hard to tell from the video) Its quite possible a valve and piston touched bending the valve slightly and creating a massive valve clearance - the cam belt may have skipped a tooth while exceeding max rpm? if this is the case a compression check will reveal low compression on one cylinder. It might be worth pulling the belt covers and seeing if everything is still timed up correctly. I'll wager its not.
Check belt marks as above, if ok pull the plug lead off one pot and see if it still runs? This will indicate all is well with the other pot - do the same for the other, cutting out will indicate low compression on that pot.
Although I have done that, it can b*gger up the CDI units.... Anyway...it sounds like either the alternator or clutch centre nuts have loosened..... Or what Pete says, below AL.
I agree with this , I was taught never pull a cap off without earthing the plug, 1/ it can give you a shock b/ it can bugger up the CDI unit
I've heard a similar sound before when a clutch bolt worked its way loose, came undone and the drum then spent its time mangling the bolt and spring. The fact that you say it ran fine and that you rode it home indicates to me that big ends, pistons, belts etc are all probably OK. Good luck
Put your hand on the clutch cover, start the bike and you may well feel the mangled stuff a'mangling and a'jangling as they get tumbled around inside the cover. If it is that, you'll know its then a very quick, easy cheap fix and you can check all the other clutch springs at the same time.
**UPDATE** You're all wrong! As was I, I should probably listen to my Dad more often, he got it spot on from listening to it. it was a gudgeon pin failure on the bottom cylinder. Which makes a lot of sense as the bike ran fine with no power loss, so it was never going to be valve related. I've kept the engine is top nick, and the tolerances in the heads are still all lovely and there was no contact between valve and piston at any point. However! this does leave me one knackered piston and a nicely scored bore. the scraper ring is also trashed so can't reuse that (probably not a good idea to anyway, but at £70 a cylinder from Ducati it's awfully tempting). so they'll have to be replaced. I split the block and the swarf was minimal, bottom end is solid, the plain bearing in the top of conrod took the hit so thankfully the rod is straight and true. I hope this helps anyone who encounters this noise on their Supersport, I'll just have to take note to give her a few more miles to warm up when the temperature is only 5 degrees! here is a pic of the damage to the piston, what you can't see from the picture is the gudgeon pin hole is oval!
I apologise. 'ChewyTheKneeslider' was right with his diagnosis. and to iterate his thoughts, there was no debris in the combustion chambers.
Glad it's not too bad and with respect Jacques, we couldn't inspect and try different theories 'in the flesh' like you two could though? :wink: also failure of the pin itself is a very rare occurrence (FPE/IMO) - I would love to see more pictures of the remainder of the pin particularly around the failure/break area. I have E-mailed you back re: engine but i don't know if you got reply. Best regards Chris
I'll be a more specific about what failed for those that are interested. If you look at the picture of the piston above, to can see the metal has torn around where the circlip that holds the gudgeon pin in sits, what's happened is that for whatever reason, the circlip has been forced out by the gudgeon pin, and then the gudgeon pin has slid out until it's met the wall of the bore, where it's scored it. The gudgeon pin itself is actually unscathed to look at, the bearing surfaces are actually fine, and the old test of rolling it on a flat surface don't highlight any obvious signs of fracture or misshapenness, but I'll replace it for peace of mind. Also, the circlip was found stuck to the magnetic sump plug, it's intact and not misshapen at all! lucky or what? I wasn't looking forward to checking the bottom end for bits of it. So, perhaps it's fair to call it a piston failure? I called it a gudgeon failure simply because it wasn't that dramatic.
sounds more like the actual circlip has dislodged Jacques? - reasons for this can be many but it is a fairly regular 'fail' on engines generally.
Maybe soemone had it apart in the past, and put it back together with the old gudgeon pin circlips? Thats the only time I have ever heard of one failing like that. My dad had a Velocette Viper many years ago, which spat out a circlip when he re used a old one after a rebuild. Shame, if you needed a 900ss piston, I have a good second hand one of those knocking around which you could have gratis.
It does rather look like the piston has failed on the outer edge of the circlip groove, doesn't it?.....You can actually see the shape of the end of the circlip 'cut' into the piston. Otherwise, there was some thrust on that gudgeon pin..... A circlip that has been reused; badly fitted or the groove not cleaned before the clip was fitted are all quite understandable; but being pushed out unscathed seems a bit bizarre. AL
