'78 darmah sd - what's this noise?

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doug s.
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'78 darmah sd - what's this noise?

Post by doug s. »

hi all!

what's this noise? it sounds bad. the clacking noise, not the nice exhaust rumble. i did break the chain on the ride, but about 10 minutes prior, when at idle at a traffic light, i thought i noticed the noise; i ride w/a full faced helmet and earplugs, so it wasn't obvious?

or is this noise solely due to cruising at ~50mph and then accelerating to pass someone, which is when the chain snapped, and the engine suddenly stopped?

i recorded this when i started the bike up after it was towed home...

https://photos.google.com/photo/AF1QipO ... fJzOsCYmwS

thanks for any help.

doug s.
(also posted to the f/b ducati bevel owners page)
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Re: '78 darmah sd - what's this noise?

Post by robax »

That link isn't working
Rob - NZ
-------------------------------------------------
1982 Ducati 900ss
doug s.
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Re: '78 darmah sd - what's this noise?

Post by doug s. »

strange, works when i click on it.

lemme try again

https://photos.app.goo.gl/MiuTSWUNeufkrnPc8
'you may have to use google...

doug s.
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Re: '78 darmah sd - what's this noise?

Post by BevHevSteve »

Tough to tell but definitely something is not right -

Check the EASY stuff first.

-> Check your oil level.. Are you very low on oil?

exhaust leak? Check tightness of exhaust nuts.
valve adjustment? Check

You can get a stethoscope with a long rod at the end, and set up against the motor various places to determine if the sound is from the head or crank etc.
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doug s.
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Re: '78 darmah sd - what's this noise?

Post by doug s. »

hi steve,

well, the noise is definitely on the bottom, not the top. (you may have noticed how the noise decreased in the vid i took, when i moved my phone over the tank, to get to the right side of the engine.) it does sound a mite louder on the left side.

one other thing - before i took my ride, i'd had the bike idling outside (~75f outdoor temps) for a while, trying to see if i had any leaks, as the garage floor was oily. the oil must've been from something else, as there were no leaks whatsoever. which i found odd, because there was oil on the motor, which i hosed off when the bike was warm. but, no leaks anywhere, after a half hour of sitting (and also riding).

but i also noticed the bike was then hard to start - i guess it didn't like idling for 15 -20 minutes. and then, i had to adjust the clutch lever, as it was engaging even when the clutch was pulled - it would want to move in 1st gear w/the clutch in. once i started to ride the bike, that stopped, and everything was fine for the 1st 30 minutes or so of riding, mostly ~60mph, w/no stopping, until i hit a small town and thought i noticed the noise, about 10 minutes before the chain snapped.

thanks,

doug s.
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Re: '78 darmah sd - what's this noise?

Post by BevHevSteve »

I would:

check the oil
check sprocket locknut for tightness
check main nut holding clutch basket for tightness
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doug s.
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Re: '78 darmah sd - what's this noise?

Post by doug s. »

thanks, steve; will do.

doug s.
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Re: '78 darmah sd - what's this noise?

Post by doug s. »

ok, so the oil level's fine and the sprocket locknut is secure.

being relatively inexperienced, to make sure i'm checking the right thing, it's this part, which i will access by pulling off the starter motor cover and the left side crankcase cover?
- TAV03.19 - 72515.0827 - Nut - M8x5

also, check out this noise; rocking the sprocket back-n-forth with my fingers, sounds like what i hear when it's running:
https://photos.app.goo.gl/M4BSf2Kw51p9qR3w5

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Re: '78 darmah sd - what's this noise?

Post by BevHevSteve »

0400.47.040 M20 nut that holds the clutch basket on. It seems that a common thing to happen is that it loosens up....

clutch cover has to be removed, all the clutch plates removed then you can check that it's tight.
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doug s.
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Re: '78 darmah sd - what's this noise?

Post by doug s. »

thanks, steve.

i never got that far; here's what i found when i removed the starter cover:
ducati darmah - nut came off, reduced size .jpg
the nut on the spindle that turns over the motor was off the shaft. no noise w/the engine running, now that it's back on; also no noise when turning the chain sprocket by hand, per my 2nd video.

but, after i buttoned it back up, i then checked the service manual and parts list; according to those, there should be a shim/bush between the sprocket ring nut, and the starter motor cover? and a washer after? (and similar on the starter motor shaft?) and the washer between the ring nut and the sprocket should be a lock washer? the washer there was completely flat, not wavy. there were bronze bushes in the starter cover for the starter motor and the spindle that turns over the engine, but it seems these aren't the shims being referred to, in the service manual? the parts manual is less clear. i didn't see or hear anything fall out, or into the crank case cover, is what i have ok? should i pull everything off again, including the left side cover to see if anything fell in there, when i pulled the starter cover off?

also, i did use permatex med strength blue gel threadlocker on the sprocket ring nut/shaft.

thanks again,

doug s.
doug s.
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Re: '78 darmah sd - what's this noise?

Post by doug s. »

well, to be safe, i opened everything up again, and got into the clutch - no issues there (and no parts dropped down from the starter). i buttoned everything back up, and while i still hear a clacking, it's not really that bad - maybe it's always been there, and i'm just overly sensitive, since i snapped the chain?

also, interestingly enough, the starter motor chain had its retaining clip on the inside; i wonder what the mechanic did when i had my used rebuilt starter installed a couple years back, along w/the valve adjustment?

thanks,

doug s.
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Re: '78 darmah sd - what's this noise?

Post by doug s. »

one final thought -

the only thing i'm wondering about is the larger shaft/sprocket that the starter engages to turn over the engine - there was some fore/aft movement when the starter cover was off. (not slight left-right movement, from the bike's orientation, but fore-aft movement, which is allowing the starter chain to go slack or tight). is this normal, or should it be in there rigid?

thanks,

doug s.
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Re: '78 darmah sd - what's this noise?

Post by 81mhr900ss »

The outer cover has two bushings, one for each shaft to engage so with the cover on, there should be no play in the sprocket shafts.
doug s.
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Re: '78 darmah sd - what's this noise?

Post by doug s. »

thanks, steve.

yes, i'm sure there's no play in the larger sprocket shaft when the cover is on; i was wondering about when it was off; if the front-to-back play is normal, so that the chain gets some slack when the sprocket/shaft is moved forward.

thanks again,

doug s.
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Re: '78 darmah sd - what's this noise?

Post by BevHevSteve »

normal slop in the system without the cover in place. Also there should be a small shim on each so you don't wear through the cover.
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