Ducati Monster Forum

Moto Board => Tech => Topic started by: booger on August 31, 2009, 08:59:28 AM

Title: Urgent valve adjustment question
Post by: booger on August 31, 2009, 08:59:28 AM
I'm into the valves now, and for some reason I cannot depress the closer rockers on any of the valves. They just won't depress, or they will so minutely that I can't notice. However I can still spin the closer shims with my fingers. I'm using the Ducati shop manual and the LT Snyder book coupled with pertinent forum threads on the subject, and am certain of TDC. Belts are off. Bike's an '06 S2R800 w/ 6650 mi. I tend to ride hard. Right now I have three openers beyond spec but the rest are OK. I just can't believe that there could be no wear on the closers. I will double check the clearances this evening, but is it possible to not be able to depress the closing rockers? That would imply a less than .001" clearance on all of them which is perfect and seemingly impossible. Any help appreciated, thanks
Title: Re: Urgent valve adjustment question
Post by: CX500 on August 31, 2009, 09:35:13 AM
The ideal clearance for the closers is actually  .001" or less.  Difficult to measure.
It sounds like you are aware of the "light" spring that holds the closing rocker against the shim (helps starting).  The rocker has to be pushed down to read the clearance.  Even with a small clearance you should be able to feel the rocker move a bit when you push on it with something solid.  When pushing the rocker, the closing shim should spin freely.  If not, you are too tight.  If it spins, but you  can't fit a .002 or .001 shim in, then you are perfect on clearance.
Keep in mind that the "light" spring is fairly stout compared to finger pressure.  I use a brass rod to avoid scratching the rocker when I push on it.
IIRC, when valves wear, the closers tend to open up and the openers tend to close up.  (That is the most confusing sentence I've ever written!!).
The closers get looser over time.  The openers get tighter.  Not every time though.
Title: Re: Urgent valve adjustment question
Post by: booger on August 31, 2009, 09:48:15 AM
I can push on the closing rocker with all my might and it doesn't seem to budge. Can't fit my smallest feeler btween closer shim and rocker. However I can spin the closer shim with my fingers without putting any pressure on the closing rocker. They spin with fingers, but not freely like a ball bearing. It takes some work to spin them but they do spin with no binding. I should mention they all feel the same like that.
Also one of the openers that were out of spec was of a darker metal, unmarked unlike the others, and had been sanded unlike the others. I think a double check is in order, but I checked them all thrice yesterday.  ???
Title: Re: Urgent valve adjustment question
Post by: Slide Panda on August 31, 2009, 09:52:50 AM
Do you have the belts on? Are you trying to press the rocker down against the cam?
Title: Re: Urgent valve adjustment question
Post by: booger on August 31, 2009, 10:00:12 AM
Belts are off. Maybe rotate the cam pulley slightly as I'm pushing on the rocker to check if they will depress?
Title: Re: Urgent valve adjustment question
Post by: CX500 on August 31, 2009, 10:04:59 AM
One otber thing to check for (I've done it) is to make sure you are at TDC of the compression stroke.  There are two TDC's, and one will have cam tension on the valve.
Title: Re: Urgent valve adjustment question
Post by: booger on August 31, 2009, 10:26:28 AM
Well I'm pretty sure I'm @ TDC compression from the marks on the pulleys and in the sightglass. I'm lining up the black tickmark on the flywheel with the arrows in the sightglass, dot on the center pulley is lined up with the mark on the case, at this point the mark on the horizontal pulley lines up with a screw at the top side of the horiz cam rubber housing, and the vert pulley mark lines up with a small round rubber knob on the vert cam rubber housing. At this point I'm assuming TDC horiz compression, and can see the top of the piston through the spark plug hole. Rotating 270 CCW from this position I assume puts me at TDC comp on the vert cylinder, as the vert pulley mark lines up with a mark made with a green paint pen I'm assuming at the factory.
Title: Re: Urgent valve adjustment question
Post by: seevtsaab on August 31, 2009, 11:52:59 AM
I'm hardly-a-expert but I found it pretty easy to determine TDC stroke by
air pushing out of spark plug hole (confirmed by marks etc)

I checked my closers with belts on, though I can't recall #'s, there was a differece,
I noted I'm marginal for adjustment.

I was in on a recon mission and plan to go back in, now armed with shims, was pretty nervous about rotating the cams and forever rendering my monster inop.

I used a 1/4 socket drive with a small 11/32" or whatever socket to press the rocker, pretty stiff untill you've done it a bunch I'm sure.

good luck
Title: Re: Urgent valve adjustment question
Post by: gage on August 31, 2009, 12:47:04 PM
With the belts off it makes zero difference where the piston is.

TDC prevents the valve from falling down to far.

TDC is important when putting the belts back on.

Title: Re: Urgent valve adjustment question
Post by: EEL on August 31, 2009, 01:10:54 PM
Personal experience and MY opinion only (FOR CLOSERS)

I dont measure .001". I've tried and you really cant do it as accurately as you can do it by feel. If the shim is way off I can measure it easily. But for small clearance issues (which most of the time they are), the way I do it is to pull the rocker arms for both openers on one head to the side and spin the cam (w/ belts off). If it binds, then you know ONE of the closers is too tight. Then all you have to do is isolate which one is tight. Believe it or not tight is good for measuring because then all you have to do is sand down the shim to make it work perfectly. Loose means you need another shim.

Since shims are generally bought increments of .05mm and if said measurements are loose and in the .001"-.002" range. Buying an incrementally larger shim usually works out fine.

In the end I just sand down the tight shim little by little until the closer doesnt bind. Then you proceed to spin the shim in increments of 10 degrees and spin the cam again to see if uneven sanding has resulted in any tight spots. Once you can spin the shim all the way around in 10 degree increments without binding, you have attained as close to a zero clearance on the closers as you will ever get.

Its more tedious but its as exact as you can get. Being the anal bastard that I am this is the only way I can guarantee a quality job. No shop will ever do this because it takes too long.
Title: Re: Urgent valve adjustment question
Post by: Norm on August 31, 2009, 02:31:27 PM
Sounds to me like your closers are perfect. Go for a ride and have fun.
Title: Re: Urgent valve adjustment question
Post by: ducpainter on August 31, 2009, 02:58:34 PM
Quote from: Norm on August 31, 2009, 02:31:27 PM
Sounds to me like your closers are perfect. Go for a ride and have fun.
I agree with Norm. It sounds like they're fine. Go ride it.

From a technique perspective, to 'measure' the closer gap you want to take a measurement between the opening rocker and shim with the closer depressed. The difference between the loaded and unloaded measurement is the closer clearance. There's no way you'll get an accurate measurement between the closing rocker and shim.
Title: Re: Urgent valve adjustment question
Post by: gage on August 31, 2009, 03:43:45 PM
Quote from: EEL on August 31, 2009, 01:10:54 PM
Personal experience and MY opinion only (FOR CLOSERS)

In the end I just sand down the tight shim little by little until the closer doesnt bind. Then you proceed to spin the shim in increments of 10 degrees and spin the cam again to see if uneven sanding has resulted in any tight spots. Once you can spin the shim all the way around in 10 degree increments without binding, you have attained as close to a zero clearance on the closers as you will ever get.



If you don't have the patience for this  :o you can get a thick piece of glass and tape some wet/dry sandpaper to it and then sand the shims. This works for me.
Title: Re: Urgent valve adjustment question
Post by: EEL on August 31, 2009, 04:09:15 PM
I probably wasnt clear but I sand the shims as well using the same method you are proposing.
Title: Re: Urgent valve adjustment question
Post by: booger on August 31, 2009, 04:47:17 PM
Measured them again, and I have two loose closers, one tight opener, three loose openers, and two spec closers. Apparently I needed a valve adjustment. I just wasn't doing it properly. CA Cycleworks saved ma ass
Title: Re: Urgent valve adjustment question
Post by: booger on September 02, 2009, 04:47:07 PM
'06 S2R800 6650 miles

OK- while I was in there today I wiggled the valve stems and it seems that they all have a little bit of wiggly going on. Now I'm scared. How much axial play should they have? Bike ran fine, didn't use oil, valve stems and seals look good, however at the horizontal exhaust there was some sludge that collected up against the valve cover and this sludge seemingly consisted of a bronze particulate matter. Had some trailer-hitching at lower rpms but pulled like a train above 4500. Bike's had it's oil changed three times in 6650 miles. Whether or not the guides are toast I'm going to finish the valve adjustment(only have to buy 1 closer), reset TPS, throttle sync, VDST fuel trim it and rock on. What do you guys think?
Title: Re: Urgent valve adjustment question
Post by: Dietrich on September 02, 2009, 04:55:28 PM
My GT1000 has had sloppy loose valves for at least the last 15,000 miles (over 38,000 on it now).  I keep the valves adjusted and everything else in tune, and it runs strong.  Doesn't smoke, doesn't use a lick of oil, starts fine, etc.  I've done multi day trips, a night at the drag strip, two track days, and general floggin around town and day rides.  Many Sport Classic valve guides were replaced under warranty for premature wear.  I'm out of warranty.   I really want to blueprint a set of heads, but living in AZ just don't want to bike off the road long enough to pull the heads and get the valve work done.  Plus I want to upgrade if going through that trouble. 

I say just keep things adjusted, ride it, and keep an eye on things.
Title: Re: Urgent valve adjustment question
Post by: ducpainter on September 02, 2009, 05:09:02 PM
A Duc will run fine for a long time with 'loose' guides
Title: Re: Urgent valve adjustment question
Post by: booger on September 03, 2009, 07:01:28 AM
I am comforted by these comments. Anyone else want to chime in?
Title: Re: Urgent valve adjustment question
Post by: He Man on September 03, 2009, 12:50:19 PM
Quote from: ducpainter on September 02, 2009, 05:09:02 PM
A Duc will run fine for a long time with 'loose' guides

+1 i ran mine for a few thousand miles with loose guides. and they were probably loose for a few thousand more before i found out. Gas mileage improved a bit when they were replaced though.
Title: Re: Urgent valve adjustment question
Post by: booger on September 06, 2009, 05:32:35 PM
Well I finally got the bike put back together today and boy are my fingers tired and sore. Must have sanded for hours. No more trailer hitching before 4k but bike seems different somehow. Maybe pulls less hard? Can't tell. Need more saddle time. Been off the bike for two weeks now. I've missed it! I do know this- a 10" length of 3/8" wooden dowel to wedge the closer rocker down and another piece of hardwood as a closer rocker depressor were essential to do this job.
Tomorrow I'll reset the TPS, sync the throttle bodies and do some fuel/idle trim. Wash it down well and then I'll be ready.
Title: Re: Urgent valve adjustment question
Post by: EEL on September 07, 2009, 12:28:24 AM
Actually it isnt, use an 8mm allen next time. Wedge the short end of the allen in to keep the rocker arm depressed. I use that trick every time on my S2R 800. Also, EMS Duc produces a closer rocker arm pusher downer do-hicky. Well worth the 25ish bucks if you plan on doing this work on your own from now on.

Title: Re: Urgent valve adjustment question
Post by: uclabiker06 on September 09, 2009, 04:12:08 PM
I had the same concern w/ my valves on my s2r8.  I would say as long as your not burning oil you should be okay.  Ca Cycleworks is AWESOME.  Chris really knows his stuff and will tell you the real deal.  But as far as the valve stems go how do you know that the one valve wiggles more than the others?  Maybe your just being paranoid like me when I did my valves.  I wouldn't worry about it.

Also I felt like my bike had less low end pull when my valves were adjusted.  But I also felt like the power was spread out more evenly over the power band and definitely more power towards the high end.  Felt like the engine was working less but had more power....hard to explain but it feels GOOD; like when i first got the bike.