Motorway driving 70mph, bike sounds like its starting to run rough, possibly 1 cylinder, sounded a lot like it does when the breather pipe is blocked as I'd only just filed to the brim with fuel. Back wheel locked up. Fuel pump will prime, pushing the starter, you get a "click" and the dash lights dim, as if its trying to do something. Taken both the belt covers off as that was my first thought. Thankfully both belts are in good condition, are tight and most of all present! Makes me think its an overheated piston seized in the cylinder. But open to any other suggestions.
Seized pistons are pretty rare. Is the motor seized?? Can you turn it over by hand, or put in gear and push it? Maybe with plugs out to make life easier... If so, maybe reg/rec has died and the battery is dead hence not able to turn over. Would give rise to misfire before dying... If motor is seized, i'd guess mains or big end. Pistons rarely seize in my experience
Thanks for that, will pull the plugs and see if the engine will turn over by hand. Negative, both plugs out, bike put in gear, wont budge anywhere. Bizarrely I seem to have lost all my clutch fluid but cant see how that would effect what has happened.
The cluch assy may have fallen off, this can stop the engine turning. Take the clutch cover off and have a look.
Clutch cover is off, basket spins with the clutch lever depressed. Will strip the outer plate off and see what the condition of the nut is. bolts and springs are off, plate is free but attached to the rod, and that seems to be pretty firmly stuck. Whenever I have striped the clutch before the plate and rod have just slid out in one go pretty easily. Something to do with lack of clutch fluid? Slave cylinder is off, the recent problems with the chain have quite literally left their mark! Bit of a chunk missing and probably where all my clutch fluid has gone. Access to other end of rod, have tried tapping the rod but don't want to hit it too hard. Still doesnt want to budge.
Clutch rod is out... eventually. Both O rings are there but crumbled straight away, mid shaft there's quite a bit of scoring. Dropped the oil, sump plug has caught quite a few metal flakes, one very big, 1p size. The rest just tiny. Striped the rotor/generator side down in order to knock the clutch rod a bit further out, involved taking the gear changer off so will just carry on with the strip-down.
doesn't sound like a simple fix sadly. The symptoms could mean oil starvation to a bearing somewhere, typically a big-end (as said) as seizure was so sudden.
Balls, will keep that in mind though, thanks. Clutch hub nut kept coming loose a few years ago, so used blue locktite to hold it in place. That's come back to bite me in the ass, nearly popped an eyeball getting that thing off!
Bike's in the kitchen now ready for stripdown, ah the advantages of being single! I'm sticking with overheated piston, maybe even a bent conrod. Anyone want to bet on other things? bare in mind both belts are still whole.
I'm with Nelly on this one I'm afraid. Possibly the old favorite of the crank oil plug working it's way out and grinding away until it's free :frown:
If anyone has a strip down thread for a 748 engine as a fav link somewhere I'd be most grateful, possibly with a few notes of what to look for, ie the crank oil plug. Have worked on many car and HGV engines and so have the confidence to work on it but not really that familiar with the bike setup, have a Ducati dealership in Carlisle that I can pop over to if and when I need a specialist tool to take certain items off. But really want to do as much as I can by myself. Vblogging kit came this morning, ironically... Probably use it to document the strip-down. Just need to learn some Italian profanity for when I see what has caused the lockup!
What is the 1p size piece of metal made of ? Big end is my guess followed by one of the main bearings. With the bike in neutral does the gearbox output shaft turn when you turn the back wheel ?
Gearbox output shaft, the shaft the clutch assy is fixed onto? then yes it does. As soon as any gear is selected however the back wheel locks up. Have removed the spark plugs to see if that would help but no. Looks like bearing shell surface to me. Makes me feel ill...
I would remove the flywheel side cover . see if thats come off. A seizure is usually caused by pistons , as you have already said , or breakage such as end of crank or nut coming off usually mains or big ends start rumbling as the get slacker .
