After successfully dealing with fuel delivery probs and finally riding for a few days, something worse rears its head...
Today on the way to work the bike began making a very difficult to describe noise... like an oscillating "supersound" above the engine, higher pitched, not a squeal, more like an unlubricated sewing machine running at high speed layered over the top of the engine. It came and went with no discernible relationship to clutching, throttle or anything that I could determine. :(
For better or worse I decided to risk making the trip home. There was more of the same "oscillating sewing machine" and then worse... tink...clak...tunk... not too loud but exactly how you'd imagine a small piece of something flying around the inside of the motor to sound. The location was traveling as I could tell from the vibrations I felt through the frame and the variations in sound. I crawled home on it safely... perhaps not the wisest thing to do but I was quite close by then.
I don't have the means ATM for a service visit at the nearest shop 100 miles away.
I am interested in learning what I can possibly troubleshoot myself. I have never done a valve clearance check but planned to do so before long (the bike only has 3,000 miles on it) but I have no trouble rolling up my sleeves and poring through shop & Haynes manuals, tutorials, and sound advice from the board. I've plenty of good tools and success so far with rejetting and rebuilding the carbs and pulling the alt cover for a "shift claw" repair. And yes, that nut was torqued properly!
What's the first step, a compression test? Opening the valve covers and taking a look? I've considered getting a sound clip to post and using the "screwdriver stethoscope" technique but I fear damaging the motor further by running it, that seems to happen quite a bit.
I'd check the belt pulleys.
Loosen/Remove the belts and rotate them.
They should turn smoothly with no notchiness.
+1 on this.
Take the plugs out first to make it easier to turn
Bad news for me, with what may be one of the most expensive mistakes I've ever made.
Before pulling the belts to check freeplay on the cam pulleys I took a good look at their positions. They line up just fine with their marks, unfortunately, not at TDC.
Below are some pics that show the actually pulley positions when the window shows the motor at TDC. Yeah, they're nowhere near close. When the cam/case marks are properly aligned, the window shows the TDC mark having just moved counterclockwise out of view. I don't know whether this means they are advanced, or retarded, but I'm guessing the clinky clank sound I've heard is part of one or more valves that have struck a piston. I'd like to think that the belts slipped or something, but I checked the tension and of course it can only have been my make the beast with two backs up when replacing the belts. I'm going to check the pulley play and see if I can tell which (hopefully not both) cylinders have been affected.
I'm sure I'll be back for more advice before long. For those who can read the marks, what do you guess would happen with this kind of bad timing?
(http://i53.tinypic.com/24wy2v7.jpg)
(http://i51.tinypic.com/2ltfg7.jpg)
(http://i55.tinypic.com/zxlm2v.jpg)
Yeah...
you messed up.
The valves are definitely bent...probably both cylinders as they are both out about the same amount.
There is a possibility the guides are cracked too.
Are you going to do the work yourself?
That depends on whether someone's willing to walk me through it [laugh] Half joking. It remains to be seen, this is pretty new to me but there are a lot of resources available and I do have the time over Winter. Admittedly, my track record isn't looking the best, but my budget is stretched unbelievably tight and I may have no choice. I think would like to assess the damage and while doing so determine whether or no it is outside my capabilities to do on my own.
I checked the pulley play... vertical cylinder meets resistance, rolls over and sticks a bit, then rotates and rolls over again. Same each rotation...resistance, roll, slight stick, roll... repeat
Horizontal cylinder pulley, rotates 60 degrees or so and comes to full stop.
FAIL.
I totally dropped the ball on this diagnosis. I got to wondering how I could possibly have turned the crankshaft while changing the belts without some effort and it just didn't make sense, I'm pretty anal retentive about such things. So I put the belts back on (the crank hadn't turned since) and aligned them precisely according to the pics I snapped as reference, and then turned it over until the cam pulley marks hit the case targets. Then I rechecked the TDC mark in the view window. Spot on!
I had misread what I thought was TDC through the window.
Which leads to the next thing, because the reason I misread the mark is that the edge of the flywheel which has the two TDC marks cut into it, is abraded in several places. This is why I read it wrongly.
I'm reminded of the loose flywheel nut issue I joked about above, I'm wondering if its come loose and is banging around in the case. This would explain why the bike didn't seem to lose any power on the ride home after it started making this gawdawful noise. I'm thinking that the easiest check I could do would be to pull the case and check. What else could abrade that lip on the flywheel apart from it coming loose and grinding on the inside of the case or having a loose part hit it?
Also, it occurred to me that the reason the horizontal cylinder pulley wouldn't spin is because the valves were hitting the cylinder head at TDC? Duh... Bear with me, it gets better!
Did you just change your belts? If they are too tight they can make that noise. After replacing mine and tensioning them correctly the engine was making a sewing machine sound. I rechecked the tension to make sure I did it right but the noise was still there(was using the 5mm method). I loosened them a bit and they were fine.
Just a thought...
Quote from: Raziel on October 12, 2010, 07:20:52 PM
That depends on whether someone's willing to walk me through it [laugh] Half joking. It remains to be seen, this is pretty new to me but there are a lot of resources available and I do have the time over Winter. Admittedly, my track record isn't looking the best, but my budget is stretched unbelievably tight and I may have no choice. I think would like to assess the damage and while doing so determine whether or no it is outside my capabilities to do on my own.
I checked the pulley play... vertical cylinder meets resistance, rolls over and sticks a bit, then rotates and rolls over again. Same each rotation...resistance, roll, slight stick, roll... repeat
Horizontal cylinder pulley, rotates 60 degrees or so and comes to full stop.
You'll need machine shop services to cut the seats and do any other necessary work, but there are plenty of people here to help with the dis/reassembly.
First step is to decide if you want to take it on, and then start tearing it down.
The symptoms on that horizontal pulley kind of affirm bent valve/s.
QuoteHorizontal cylinder pulley, rotates 60 degrees or so and comes to full stop.
Is that the same now?
And it wont rotate, even w some force?
Quote from: greenmonster on October 13, 2010, 07:45:39 AM
Is that the same now?
And it wont rotate, even w some force?
I think he is sayin that after he set the horizontal cylinder at TDC he took off the belts and tried to rotate the horizontal pulley. He can only rotate it so far by hand until a valve hits the cylinder.
I *think* that's right... at TDC the horizontal cyl pulley won't move outside of an arc that is 90 degrees from either side of the tick mark at the top. So... 180 degrees total
When the vert cyl is at TDC the horiz pulley won't move much at all, maybe 20 degrees or so.
When the tick on the horiz. pulley is between the two TDCs, then I can spin the horizontal pulley all the way around. It resists, then spins on its own, stops, and I can spin it again. I guess I'd have to know how it is supposed to feel.. I can definitely feel several distinct positions: free spin, resistance, spins on its own, slightly less free spin, resistance, spins on its own. repeat. Does that make sense?
Quote from: Raziel on October 13, 2010, 05:19:00 PM
I *think* that's right... at TDC the horizontal cyl pulley won't move outside of an arc that is 90 degrees from either side of the tick mark at the top. So... 180 degrees total
When the vert cyl is at TDC the horiz pulley won't move much at all, maybe 20 degrees or so.
When the tick on the horiz. pulley is between the two TDCs, then I can spin the horizontal pulley all the way around. It resists, then spins on its own, stops, and I can spin it again. I guess I'd have to know how it is supposed to feel.. I can definitely feel several distinct positions: free spin, resistance, spins on its own, slightly less free spin, resistance, spins on its own. repeat. Does that make sense?
Yes...
When you spin the pulleys you are overcoming the assist spring. That is the resistance you feel. When it spins by itself the assist spring is closing the valve.
The fact that the horizontal pulley won't spin all the way around (dependent on piston position) is a problem.
You didn't fail - like you said you picked the wrong mark in the sight glass. I could tell that from the first photos. The drive pulley was off, but the others were off the same amount - so it looked good to me.
mitt
Also, I think you are not finding horizontal TDC correctly. The tick mark on the crank is for TDC vertical if my memory is correct. Then rotate the crank 270 degrees - that will get you to TDC for the other cylinder. The cylinders are 90 deg apart, not 180.
mitt
Thanks Mitt I will have to look at it again, it seemed as though the difference b/w the two marks in the sight glass resulted in 180 degrees difference on the pulleys, but I obviously need to take a closer look. Even so...
Quote from: humorless dp on October 13, 2010, 05:22:36 PM
The fact that the horizontal pulley won't spin all the way around (dependent on piston position) is a problem.
So... both pulleys should rotate 360 regardless of piston positions? Back to the bent valve/damaged valve guide scenario. :(
I assume that just because the vertical cylinder pulley can spin 360 (haven't checked it in all positions)
doesn't guarantee there's no damage there either.
Time for some research. I've got the Haynes 91-96 2-valve manual and the Ducati shop manual and will look for other resources. What else could be done before the head is removed for inspection? It doesn't seem like you'd be able to tell much by looking at the valves from the rocker side unless the damage were pretty severe, but it seems like the obvious next step.
It's time for the heads to come off.
Sorry.
I still think that the timing and valves are OK. Why do you think the heads need to come off? The cams should not be able to spin at TDC - that is normal. If you can get them to spin when the cylinder is a bottom, then they are OK.
Rather than spinning the cams separately, I like to pull the plugs, put the belts on - making sure all the pulley tick marks are lined up like in the OP's original photos, and then using a crank turning tool, with the plugs out, and bike in neutral, gently spin the engine and feel the pressure or suction on the plug holes with a finger to see if your strokes are inline with a 4 stroke cycle.
mitt
I agree with Mitt. The cams were off but so was the layshaft. I would remove the plugs, back the motor up to where the layshaft lines up and try to turn the cam through on the horizontal cylinder. On my bike it will turn all the way through in this position. If it doesn't bind put the belts back on and check compression. Good compression = straight valves.
Quote from: Porsche Monkey on October 13, 2010, 08:00:19 PM
I agree with Mitt. The cams were off but so was the layshaft. I would remove the plugs, back the motor up to where the layshaft lines up and try to turn the cam through on the horizontal cylinder. On my bike it will turn all the way through in this position. If it doesn't bind put the belts back on and check compression. Good compression = straight valves.
[thumbsup]
I just want Ole Grumpy to be wrong. ;D
QuoteI agree with Mitt. The cams were off but so was the layshaft. I would remove the plugs, back the motor up to where the layshaft lines up and try to turn the cam through on the horizontal cylinder. On my bike it will turn all the way through in this position. If it doesn't bind put the belts back on and check compression. Good compression = straight valves.
+1.
Simplest way, I think:
Move pistons til none of the 2 is near TDC, just feel that w a screwdriver. Remove belts.
If both pulleys rotate 360, put belts back & check compression.
If that`s good, you`re fine.
Quote from: mitt on October 13, 2010, 07:18:25 PM
I still think that the timing and valves are OK. Why do you think the heads need to come off? The cams should not be able to spin at TDC - that is normal. If you can get them to spin when the cylinder is a bottom, then they are OK.
Rather than spinning the cams separately, I like to pull the plugs, put the belts on - making sure all the pulley tick marks are lined up like in the OP's original photos, and then using a crank turning tool, with the plugs out, and bike in neutral, gently spin the engine and feel the pressure or suction on the plug holes with a finger to see if your strokes are inline with a 4 stroke cycle.
mitt
If the cam won't rotate 360
0 with the piston at TDC what is the obstruction?
Quote from: Porsche Monkey on October 13, 2010, 08:21:53 PM
I just want Ole Grumpy to be wrong. ;D
I want to be wrong in this instance.
You could line up the marks...don't worry about tdc...just line up the layshaft mark and see if the upper pulleys line up with their respective marks.
If they do then pull the valve covers on the horizontal cylinder and check to see if you have a loose valve clearance. Chances are it will be very loose if there is the problem I think there is.
If they don't then pulling the head would be in order IMO.
Quote from: humorless dp on October 14, 2010, 04:18:17 AM
If the cam won't rotate 3600 with the piston at TDC what is the obstruction?
I want to be wrong in this instance.
At TDC, the piston is at the top of its stroke - it should hit the valves at TDC...
I just changed my belts 2 weeks ago, so this is still somewhat fresh in my gray matter. My horizontal cam will not turn much when I have all the pulley tick marks lined up.
Agreed with the suggestion of using a piece of stiff wire or something to feel through the spark plug hole and the OP get familiar when the piston is at the top or bottom of stroke, intake, exhaust, and compression order for each cylinder.
mitt
You guys all may be right after re-reading.
I've been wrong before, and in this case I hope I am.
To the OP, did you change your belts before this 'noise' appeared?
Also, how is the bike running? Normal power and all?
Quote from: humorless dp on October 14, 2010, 06:31:33 AM
...
Also, how is the bike running? Normal power and all?
good question, how is the bike running? pretty much all the issues that have been talked about would give you either a no-start, or serious performance issues...
had loose flywheelnut on my 99' 750.
funny noises good power still.
flywheel ground the pointer in the window alittle.
Wow! Quite a lot of excellent posts to go through and all with good information! Thank you most kindly everybody. I have no interest in proving "Grumpy" wrong, but yeah, I hope you're wrong too mate! I appreciate your help.
Quote from: OT_Ducati on October 14, 2010, 05:31:34 PM
had loose flywheelnut on my 99' 750.
funny noises good power still.
flywheel ground the pointer in the window alittle.
I'm leaning toward this idea as it meets everything I've observed above and confirms that it's possible.
It was the minor cacaphony of clinks and clanks that accompanied me on the ride home from work which started this whole thing, and the bike hasn't been run since. I didn't feel any change in revs, torque, pull, etc. while doing so, though I was most def babying her those few miles. Apart from the noises it seemed to be running fine.
But at this point, I have no plans to button her back up and start her again until I know with certainty that I have the cam pulleys in their proper position relative to the crank for fear of doing new or further damage, and I am not confident I understand the stations well enough to be sure that I now have everything in its proper place after having fiddled around so much. I need to understand the relative positions of the pistons that Mitt referenced before doing so. I need to know the proper baseline to check the amount of pulley travel between TDC's.
I'd like to understand the mechanics of the travel...please forgive my ignorance but I must learn this and if anyone would like to share their knowledge it would help me immensely. Here are my questions:
A. One 360 degree revolution of the main pulley/layshaft/crank from TDC = what? One half of the 4 stroke cycle? I.e., suck and squeeze on one full revolution, and bang and blow, on the second? Or the full 4 strokes in one 360 degree revolution? Also, Mitt has written that the case marking for this pulley indicates TDC for the rear/vertical cylinder. One can then assume that the cam pulleys should be set by rear cylinder TDC, and suggests the full four strokes in a single revolution.
B. What does a 360 degree revolution of each cam pulley accomplish? Half, or the full four stroke cycle? From what I gather a full cycle would be one extension and one retraction of each valve per head, each cycle.
So I am grasping for straws a bit, but I can learn quickly through explanation. If it must learn this empirically by checking piston position with a screwdriver through the spark plug holes as has been suggested, that's no problem, but understanding where the individual components are expected to be during their respective cycles, and the frequency of said cycles vis a vis pulley position, would greatly help me to understand what I am observing.
And if there is a shortcut or easier means of getting it through my thick skull, I'm all ears. Thanks again all.
My advice with regard to belt timing is not to over think it.
Line up the layshaft mark on the case and see if the cam pulleys line up with their respective marks. Crank position is automagically in the right place. It is designed that way.
If they do you have no belt issue...if not...pull the valve covers and check for a really loose valve clearance.
If they do line up it could be a multitude of problems.
as far as a quick thing you could check to see if the flywheel nut is loose, don't ask me why, but the clutch pushrod is usually broken, sheared in one spot into two pieces. Something to do with increased vibrations or some other magic thing, but it's a good sign that's super easy to check without having to tear open the side casecover...
I know, it sounds completely unrelated, but worth at least a looksee...
Quote from: humorless dp on October 14, 2010, 06:55:20 PM
Line up the layshaft mark on the case and see if the cam pulleys line up with their respective marks. Crank position is automagically in the right place. It is designed that way.
They did line up, which you can extrapolate from the pics above, and apparently they can be returned to that position without fear of being off by one rotation on any of the three pulleys. Gotcha.
Which can only mean that one full revolution of the layshaft/pulley equals four strokes/one full cycle for both cylinders. EDIT: The following is flat-out wrong, for anyone playing the home version. Since the layshaft tick mark indicates true TDC for one of the two cylinders (likely the rear vertical)
then only two positions of the layshaft/crank should allow unrestricted movement of the valves by turning their respective cam pulleys -- those being 90 and 270 degrees. At zero and 180 degrees, both cylinders are at TDC: one compressing, one exhausting, and either or both will limit valve and thereby cam pulley travel.
Think I got it, but someone please correct me if I don't. Tomorrow I will align the ticks again and fire her up after confirming free pulley travel at those positions. But not until I've looked into this...
Quote from: hiero on October 14, 2010, 08:24:04 PM
as far as a quick thing you could check to see if the flywheel nut is loose, don't ask me why, but the clutch pushrod is usually broken, sheared in one spot into two pieces. Something to do with increased vibrations or some other magic thing, but it's a good sign that's super easy to check without having to tear open the side casecover...
That's a brilliant tip, I will have a look! Thanks.
The two cylinders are not at tdc at the same time.
If the marks line up forget about that being the problem.
Look elsewhere.
Please illustrate. A simple explanation of what transpires during a full revolution of the layshaft would suffice.
Quote from: Raziel on October 15, 2010, 07:15:59 PM
Please illustrate. A simple explanation of what transpires during a full revolution of the layshaft would suffice.
One revolution of the layshaft is two crank revolutions. A 4 cycle/stroke engine requires 2 revolutions of the crank for a combustion cycle. The layshaft spins at half crank speed so it's mark will always line up at tdc of the compression stroke for the horizontal cylinder.
The two cylinders are not at tdc together. Otherwise you wouldn't have to overcome the assist spring on the vertical cylinder to install the belt.
I don't know how many degrees of rotation apart the 2 cylinders are. Someone here does.
You can verify what I say by lining up the mark on the layshaft and sticking a screwdriver in the plug holes. The horizontal will be at tdc and the vertical won't.
Quote from: humorless dp on October 15, 2010, 07:32:09 PM
I don't know how many degrees of rotation apart the 2 cylinders are. Someone here does.
The pistons share the same crank pin
(http://desmobalance.com/images/A-crank_750_Zahnriemen.jpg)
And, the cylinders are 90 degrees apart
(http://image.sportrider.com/f/16606354/146_0901_05_z+2009_ducati_monster_1100+desmo_engine.jpg)
So, if one cylinder is at TDC, the other is 90 away from TDC. If on cylinder is a bottom center, then the other is 90 deg from that, etc etc.
mitt
Quote from: mitt on October 16, 2010, 08:00:17 PM
The pistons share the same crank pin
(http://desmobalance.com/images/A-crank_750_Zahnriemen.jpg)
And, the cylinders are 90 degrees apart
(http://image.sportrider.com/f/16606354/146_0901_05_z+2009_ducati_monster_1100+desmo_engine.jpg)
So, if one cylinder is at TDC, the other is 90 away from TDC. If on cylinder is a bottom center, then the other is 90 deg from that, etc etc.
mitt
[bang] [bang] [bang] [bang] [bang]
that makes waaaaay too much sense. ;D
check the flywheel nut