'78 darmah sd - what's this noise?

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

Post by doug s. »

thanks, steve.

normal slop is good news. no shims is bad news; there were none there. are replacements available? but, i'm not sure how the shafts could get to the inside of the cover; the shaft w/the larger sprocket wouldn't pull out towards the left side of the engine more than ~1/4", and the starter motor shaft isn't going anywhere, and its sprocket won't move much, if any, w/the chain connecting it to the larger sprocket which is (now) securely fastened to the spindle.

doug s.
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81mhr900ss
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Re: '78 darmah sd - what's this noise?

Post by 81mhr900ss »

Interesting problem Steve. I've never had an e-start bevel but the parts drawings clearly show the two holes in the outer cover and the bushings/shims/washers that are supposed to secure the starter motor drive shaft and starter spindle ends. It's hard to tell from the drawing but maybe the holes in the outer casing stick out and into the motor.
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Re: '78 darmah sd - what's this noise?

Post by 900tlc »

Have you tried pulling the clutch in on tick over,does the noise change? The tick over is bad on your bike, the carbs need a good balance.Are the clutch plates correctly assembled,take note of the bent tangs? Have you checked the tappet clearances ? It could be top end still ,rockers gone soft and the cam.Bevel gears with too much slack in them?(sounds bad when the carbs are out of syc)
Another thing why the ear defenders??The whole thing about a Ducati twin is hearing that beautiful engine churning through the gears,unlike some other brand I could mention! What colour is the oil, if its black,and you changed it recently,then something is wearing rapidly.
Just a few thoughts on that noise.
doug s.
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Re: '78 darmah sd - what's this noise?

Post by doug s. »

re: the shims/bushes, there are definitely bushes in the outer starter case that support the two shafts. but no additional shims or washers, at least not on my bike.

re: the noise my bike makes, the bike got a tune-up and valves were adjusted ~2k miles ago. noise doesn't change w/clutch engaged or not. when i pulled the clutch donkey'y apart to check the bolt tightness, everything looked good. and the oil looks fine.

re: ear plugs, i value my hearing; i only wish i'd started using them much earlier in my riding career. i still hear the sweet sound of the motor, it's just a bit muted. it's the wind noise that's actually the biggest irritant, and this i'm happy to have muted as much as possible. i have two other bikes i enjoy riding, that make nice noises as well; my buell s2 and my suzuki dr650 set up a/supermoto wheels/suspension. both have aftermarket exhausts, and both sound nice, even w/earplugs. again, the reduced wind noise is much appreciated on this end.

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

Post by doug s. »

hi all,

reviving an old thread because i'm hearing another strange noise (w/o my earplugs - heh!); it's noticeable when i'm going very slowly - such as backed up in traffic - it seems to be related to wheel rotation, as you can hear a consistent clank/rattle noise at a steady beat as you're inching along slowly. but, it's not the wheel. i suspect something w/the clutch, as i've also noticed it sometimes will be stuck in gear even w/the clutch pulled - again, only while inching along in slow traffic.

but the problem i'm having is even getting to the point where i can remove the clutch cover to investigate. it seems i must have sealed the starter cover too tightly, as i cannot get it off. maybe i should not have used any sealant? it looks as tho it had sealant on it before, so i put it on before reinstalling.

any suggestions as to what may be causing the noise, and any tricks to removing the starter motor cover would be greatly appreciated.

thanks,

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

Post by Craig in France »

Hi Doug,

1. Don't use sealant on Bevels. It's the modern way, I know. But there's no need, and can often lead to grief. Use gaskets. But you know that ... now ;)

2. To get the cover off, start by tapping it all around the edge with a hide mallet. Hopefully this will break the sealant at at least one point. Then you're going to have to get a thin bladed knife into the joint and cut thru that sealant crap ... Heating the cover with a blow torch may also help, but go careful. Polished aluminium and heat is not a match made in heaven.

3. When refitting the clutch cover, don't forget to replace the O ring in the bottom edge of the cover .. as well as the gasket :). It doesn't normally leak, but ... (To see what I'm talking about, look in the parts book).

4. From your description, it's possible the clutch centre is coming loose. So don't delay investigating it. The clutch centre nut needs to be done up very tight. Ducati twice upped the specified torque rating, starting at 4-5kgm, then going to 7 (= 51lb/ft) and finally 10 (= 70lb/ft). This latter may be a bit of an over-reaction, however. 60lb/ft and if you're feeling nervous, a dab of Loctite, should do.

Oh - and use a new lock washer ;)
doug s.
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Re: '78 darmah sd - what's this noise?

Post by doug s. »

bonjour, craig; thanks for the reply!

so, i will try a little heat to remove the cover; the hard rubber mallet thing has already proved unsuccessful. not going to use a torch, but a hot air gun. might be a little safer.

besides the clutch center nut, on a facebook bevel forum where i also posted a query, someone mentioned selector shaft w/dogs, and springs behind the clutch assembly may be worn and/or broken?
https://tinyurl.com/2wthms5z

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

Post by BevHevSteve »

You will know more once you get the cover off, remove the clutch basket and have a look behind there...

Be very careful about using anything to pry the covers off. If you dent the alloy anywhere, you are also creating a high spot around whatever dent you *will* make which will lead to oil leaks until you file the high spots down.
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Ducati/Euro Spares -> https://Store.BevelHeaven.com
doug s.
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Re: '78 darmah sd - what's this noise?

Post by doug s. »

hi steve,

thanks for the reply. with a heat gun and tapping on a razor blade, i was finally able to get the starter motor cover off. i don't think i dented anything.

so, re: spring, selector fork, shift for eccentric and gear selector shaft - if i need these, it seems you have the correct spring, eccentric, and selector fork? (0799.13.110, 0799.13.105 & 0799.13.250), but not the gear selector shaft? (0799.13.150) any other parts i might need that you have, or don't have?

thanks again!

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

Post by doug s. »

ok, update:

and i think the fix will be a bit above my paygrade. (now if i had a real shop and real tools, maybe it'd be different...) but it will take at least a payday to get someone else on the case, i suspect. 😢

pics show the story; all the easy/inexpensive fixes look ok already - the clutch basket nut was tight, no broken springs or teeth; the washer w/the square hole was in the right place for the bike to be in neutral, etc. everything looked in order, except the shift selector shaft looked a bit loose in its place in the engine case; i thought maybe a bushing was missing? nothing came out, but a look at the parts diagram does indicate a washer should be there that isn't.

but what there *is* is the noise i've been hearing. and if i spin this for awhile inadvertently it will catch every once in a while. not a good sign. anyone know how ugly this will be?

everything looks nice:
https://tinyurl.com/47yv7ksh

sloppy fit for selector shaft in its home; missing a washer, p/n 0799.13.035:
https://tinyurl.com/yhwcp3fu

ugliness (note, it tends not to make the noise frequently; you can spin it in either direction and it's mostly quiet. but when it makes the noise, you can stop and rock the shaft back-in-forth as i did, to continue it. and as i said, once in a while it will hang up and stop):
https://tinyurl.com/yn94zsf6
(it seems to default to muted when you open it; have to unmute it; at least i did.)

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

Post by BevHevSteve »

Your links do not work for me.
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Steve Allen (925)798-BEVL[2385] Ride'm, Don't Hide'm
Ducati/Euro Spares -> https://Store.BevelHeaven.com
doug s.
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Re: '78 darmah sd - what's this noise?

Post by doug s. »

steve, i sent you a pm w/the video link; sometimes google links don't work on line. or, you can try cut/paste into your browser:

https://tinyurl.com/yn94zsf6

thanks,

doug
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Craig in France
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Re: '78 darmah sd - what's this noise?

Post by Craig in France »

Sorry Doug, but as Steve reported, your links are returning 404 or other errors.

I can confirm that you should have the washer on the selector shaft. The fact you don't means this isn't the first time this part of the engine has been opened, and by somebody who wasn't as careful as he might have been.

It's more a shim and spacer than a washer. Mine had a certain amount of wear and needed to be smoothed down in order to achieve a smooth change. The selector shaft is a loose fit in the casing, btw. No bush.

Sorry for being thick, but what is it that you are spinning to get the 'catch and clunk'?

P.s. Now that you are where where you are, you should change the gear lever return springs. The priority should be the bigger one, 0799.13.110, but it doesn't hurt to do the smaller one as well, 0799.13.120.

Also inspect the tag on the selector drum plate, 0799.13.050. The early ones used a brazed-in pin which used to fall out. So if yours is this type, make sure the pin is well secured (can you imagine the poor so-and-so who had the job of brazing those things in?). The later ones look cruder, but are better, with the tag being bent out from the parent metal.
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