In the middle of my valve adjustment at 6k miles. Started with the vertical cylinder, and found this under my exhaust valve cover. There are bits of what seem to be metal flake, but could just be the outer surface material. Lots of bubbling, looked worse before I "cleaned" it.
(http://i298.photobucket.com/albums/mm244/csorin/Motorcycle/DSC_0006.jpg)
The weird thing is that all my valves are within spec (Ducati spec at least, a little tighter than desmotimes recommends).
Exhaust Clearances (this crummy head):
Opener: .0025
Closer: .002
Intake Clearances (perfectly clean around the valve stem):
Opener: .0018 (was sticky with the .002 feeler)
Closer: .002
Just remeasured this valve again. Looks like the exhaust closer is .003, still within Ducati spec, but over Desmotimes.
It looks like cooked oil to me. The exhaust side would be hotter than the intake.
IMO your openers are tight and closers loose, but that didn't cause the issue.
Could topping up with too much oil have prevented it? Looks like there was some seapage out of one of the head bolts.
Another question for you guys. My hemostat broke. Will the valve fall all the way into the cylinder if I have the piston at TDC?
The valve will not fall in as long as you leave the piston at TDC.
What model is this?
The cooking is probably not oil level related unless you ran it very low.
If you are running dino oil it is probably that.
Likely a fairly recent bike, they'll cook the paint over the exhaust, especially on the vertical cylinder.
Quote from: Speeddog on November 06, 2010, 05:31:49 PM
Likely a fairly recent bike, they'll cook the paint over the exhaust, especially on the vertical cylinder.
My thought also.
The mapping on stock bikes is way too lean. ;)
Your photo looks familiar. Saw the same thing under my M800 exhaust valve covers. Twice. The guides were shot. Twice. In 16,000 miles.
For your own peace of mind, slide over the rocker arm, remove the opener and the closer shims and then try to wiggle the valve stem with one hand while crossing the fingers of the other hand.
When you detect no movement, post back and tell me I was mistaken.
Saw the same thing when I did my valves - I would imagine its the bronze valve guide material you see collecting at that location. Guides do wear, and you're more likely to notice at the 600/6000 mile intervals than you would be at the later intervals. Also, that location pools oil against the valve cover and would likely serve as a collection point for wear material anyway. I'd also guess that it's normal and that you shouldn't worry about it. My bike runs awesome and doesn't use oil between changes so I didn't see a problem there. My guides may be shot but the bike runs fine. ??? Adjust the valves and ride the bike.
Bike is a 2004 Monster 620. I'll do the valves, and probably just keep running it as is. So far, no problems, and it runs like a top.
So some say valve guides and others say don't worry about it?
Alright, a little more info on this. Both the vertical and horizontal exhaust head looked like this, the vertical one being the worse offender. When I pulled the closing shim off, I did notice the valve rotated. Is this okay? I didn't remember to check for a wiggle.
As for oil, the previous owner had been using some kind of diesel oil. Definitely not a synthetic, and of course not motorcycle specific. Luckily, he only had the bike for a few hundred miles.
For the last 1300 miles I've been using Motul Synthetic. The bike does have Sil Moto Slipons. Might this have exacerbated a lean condition?
Slip-ons only should not make the bike any leaner.
Do you have an oil cooler?
No oil cooler. What about the leaking head bolt? There was definite seapage out of one of the bolts. Lots of crusty old oil around it as you can see in this pic:
(http://i298.photobucket.com/albums/mm244/csorin/Motorcycle/DSC_0008.jpg)
Also, in the summer, the bike will reach temps of 275 degrees (105 ambient).
The previous owner might have been using Shell Rotella T oil for diesel engines. It is a good product.
Quote from: csorin on November 07, 2010, 02:47:58 PM
No oil cooler. What about the leaking head bolt? There was definite seapage out of one of the bolts. Lots of crusty old oil around it as you can see in this pic:
(http://i298.photobucket.com/albums/mm244/csorin/Motorcycle/DSC_0008.jpg)
Also, in the summer, the bike will reach temps of 275 degrees (105 ambient).
Head bolt isn't going to cause any crusty brown inside the valve cover.
The temp you're seeing is the temp of the oil in the cases. The cylinder head temp directly above the exhaust is hotter. A cooler would be a good addition.
Quote from: battlecry on November 07, 2010, 02:54:53 PM
The previous owner might have been using Shell Rotella T oil for diesel engines. It is a good product.
Agreed
Quote from: humorless dp on November 07, 2010, 03:05:30 PM
Agreed
Ditto for many 'Diesel' oils, for instance Mobil Truck and Diesel synthetic, if it's rated right and the correct weight....
Not to say it's ideal for the moto.
Replacement gaskets are pretty reasonable, from a site sponsor.
What does the underside of the cover look like? When I took my cover off today, I noticed that it looked like a coating, with a few bubbles. I went to touch them, and they kinda flaked off. almost like a teflon.
Underside of the cover was fairly clean actually. I did have your described "bubbles" around the valve stem and oil galley. These were cleaned off before the picture was taken.
As a follow up to the lean/rich question, I changed my plugs. The old ones were a nice light brown color, indicating a good mixture by my understanding.
For now, I'm not worrying about it. The engine runs strong, and this condition was scene on both the vertical and horizontal cylinders. I can't imagine both exhaust guides/seals, and only the exhaust guides/seals going bad.
Maybe this was the result of old oil? Either way, I'll take another look in 4,000 miles.
Quote from: csorin on November 09, 2010, 10:04:07 PM<snip>
I can't imagine both exhaust guides/seals, and only the exhaust guides/seals going bad.
Try harder to imagine that. I can certify that it's possible, and on a maintained bike. Try checking compression. Or, forget about it.