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Discussion Starter #1
I have just finished installing a 1P Nichols flywheel onto my 1996 SS/CR. I used a rattle gun to remove the rotor nut and then I torqued down the nut again to 120 ft/lbs after installing everything while being careful to align the flywheel and rotor properly. When I reinstalled the L/H cover, I noticed some resistance when rotating the crank. The resistance is a periodic slip that suggests to me that the rotor is somehow contacting the stator.

Has anybody else encountered this during the flywheel installation and, if so, how was it resolved? I am fully aware that this could be a bent crankshaft but I would be very surprised if that were possible simply from torquing down the rotor nut. I suppose the next step is to get a dial gauge and check runout on the crank end, but I wanted to solicit the forum's collective wisdom first.

Thanks!!
 

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I've yet to get deep into a Duck engine, but on the two strokes I rebuild a couple times a year I always get a little freaked out when turning the crank the first time and feeling the resistance and subsequent release of resistance as the rotor magnets pass over the armature (hope I'm using the correct nomenclature). It feels like the crank is binding.

Wondering if this is what you might be feeling?
 

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It's been a while since I looked in there. Can it be checked with a feeler gage ?
 

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Discussion Starter #6
I've yet to get deep into a Duck engine, but on the two strokes I rebuild a couple times a year I always get a little freaked out when turning the crank the first time and feeling the resistance and subsequent release of resistance as the rotor magnets pass over the armature (hope I'm using the correct nomenclature). It feels like the crank is binding.

Wondering if this is what you might be feeling?
That is what this feels like, to be sure, but I do not remember this slip/slip being typical of a 2V 900 motor. Can anybody with a (properly sorted) 900 confirm that this is normal for the motor? The last thing I want to do is to start it up and annihilate the rotor/crank.
 

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I would think if the washer was out of place you would feel it when torquing the nut. It would feel "mushy" as you tighten it and turn more than about 180 deg. or so as it bends the washer. Just a thought.
 

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Discussion Starter #8 (Edited)
I would think if the washer was out of place you would feel it when torquing the nut. It would feel "mushy" as you tighten it and turn more than about 180 deg. or so as it bends the washer. Just a thought.
I am pretty sure that the washer is in the right place -- I centered it and kept it in place with a few dabs of grease. Right now, I think that the issue is:

(1) a bent crank -- unlikely just from torquing the rotor nut, but not impossible;

(2) a misaligned L/H cover that will not sit flush against the case; or

(3) just the normal slip/slip of the rotor catching the magnets on the stator.

Does anyone have a clear answer on #3? Does your crank turn smoothly or does it slip/slip?
 

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If it is once per revolution in roughly the same place I would look at the crank. You will feel the magnetic pull from the rotor when turning slowly about every 20 deg. or so[don't hold me to the exact spacing] which is a pretty strong resistance. You might want to take a close look at the bearing in the cover too, there have been some cases of them failing.
 

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Discussion Starter #10
I finally got around to removing the motor and making a video of the engine rotation. Note that the noise you hear in the video is coming from the clutch rotation -- not on the alternator side. Following up on WDLetz186, this slip/slip resistance is constant throughout the rotation. There is no tight spot in a single position. It leads me to conclude that this is the magnetism of the rotor, but I always thought these were supposed to turn very smoothly (which it does when the rotor/cover are off.

Thoughts? Any comparisons from similar year/models?

https://www.youtube.com/watch?v=5CPW8oWYvlA
 

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I wish I could be of more help, but I still haven't opened my engine.

If I understand correctly there is no resistance at all with the cover off while turning the crank and then with the cover on there is intermittent, but consistent resistance, but no metallic, or scraping sounds?

If so all my chips are on the magnets, but please wait till someone who has experienced this with your engine chimes in before you fire it up.
 

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Discussion Starter #12
If I understand correctly there is no resistance at all with the cover off while turning the crank and then with the cover on there is intermittent, but consistent resistance, but no metallic, or scraping sounds?
Exactly correct. Anybody have a 2d generation Supersport out there that they could try out?
 

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installation issue

That sound is definitely not normal. I'd advise not starting it until it is solved.
I just personally screwed up my Yoyodyne light flywheel installation on my '98 M900. I did just what brad b. described- the thin washer behind the flywheel/starter gear slipped and got out of place. Yes, I put a big dap of grease on it but it still slipped out when I had to tap the flywheel the 2nd half of the way on, as it was tight. The flywheel nut felt fine when torqueing it up. My engine made a different metal grinding sound on the alternator side when I tried to start it. I had to take it up to my mechanic to solve- Racing Sport Services in Braselton Ga. Chris/ Hippie does excellent work and knows Ducks very well. He has a few decades of Ducati experience and said this is a common blunder! He had to replace the thin washer, the shouldered spacer behind flywheel, and the bearing for good measure.
Good luck- let us know once you figure it out.



I am pretty sure that the washer is in the right place -- I centered it and kept it in place with a few dabs of grease. Right now, I think that the issue is:

(1) a bent crank -- unlikely just from torquing the rotor nut, but not impossible;

(2) a misaligned L/H cover that will not sit flush against the case; or

(3) just the normal slip/slip of the rotor catching the magnets on the stator.

Does anyone have a clear answer on #3? Does your crank turn smoothly or does it slip/slip?
 

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We removed a Nichols flywheel and found a spacer that went in it from the crank side... Maybe it was left out? It keeps the flywheel from sitting too far back? We were putting the stock one back in and the spacer caused some issues by setting the stock flywheel out too far... Just a thought...
 

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Discussion Starter #15
That sound is definitely not normal. I'd advise not starting it until it is solved.
I just personally screwed up my Yoyodyne light flywheel installation on my '98 M900. I did just what brad b. described- the thin washer behind the flywheel/starter gear slipped and got out of place. Yes, I put a big dap of grease on it but it still slipped out when I had to tap the flywheel the 2nd half of the way on, as it was tight. The flywheel nut felt fine when torqueing it up. My engine made a different metal grinding sound on the alternator side when I tried to start it. I had to take it up to my mechanic to solve- Racing Sport Services in Braselton Ga. Chris/ Hippie does excellent work and knows Ducks very well. He has a few decades of Ducati experience and said this is a common blunder! He had to replace the thin washer, the shouldered spacer behind flywheel, and the bearing for good measure.
Good luck- let us know once you figure it out.
Noise is the rattle from the clutch basket, not the alternator assembly.

Does anybody out there with a 1993-96 900SS and a crank turning arm have a moment to check and tell me whether their crank turns: 1) smoothly; or 2) with a stutter ever 20 degrees or so. I am practically convinced that this is fine, but I want to be sure it is just the normal pull from the rotor/stator, rather than something wrong.
 

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remove the alternator cover and check the crank snout is running true (plugs out, hit start button, speed makes it obvious). if so, and there's nothing else causing it with the cover off, it can only be the alt magnets.
 

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Discussion Starter #17
Thanks, but the motor is out of the bike and I would like to get this resolved before reinstalling it. Anybody have a 1994-98 900SS or M900 who could shoot a little video of crank rotation, or shoot me a message?
 

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I've just pulled the plugs on mine ('96 SL), and turned it over by hand with the crank turning tool. It does the hold/release, hold/release exactly like your description, but I KNOW my engine is fine, so I guess yours should be OK.
 

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Discussion Starter #19
I've just pulled the plugs on mine ('96 SL), and turned it over by hand with the crank turning tool. It does the hold/release, hold/release exactly like your description, but I KNOW my engine is fine, so I guess yours should be OK.
Excellent. I heard the same regarding 1p motors from another source. This is a huge relief -- on to the head work!
 
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