Fred W, How long did this job take you? I am contemplating doing the valve check myself and after reading this entire thread, I think I will take a crack at it. I've not seen anyone post how long it took.Well, I must be using the right oil, or additives (STP) or maybe it's just clean living?
Ya right...
Things were kind of slow at work today, so I decided to go on down into the garage and crank out my 50k maintenance, including the valve clearance check/adjust.
I do everything on the 5k's, all the oil changes etc, Just makes it easier for me to remember.
Anyway, all of my clearances measured exactly what they did at 25k miles. Every intake was somewhere between .006 and .007 (an .006 feeler is a go and the .007 no-go) and every exhaust is between .008 and .009. Just like it was the last time. I had thought for sure that I would be chasing down some new shims, as there are a couple of intakes that are a tight .006, but those same valves are right where they were last time.
One added note: total parts required? Just 3 o-rings, which I already had from the first check.
Re-used the cover gasket again and never took off the timing cover (though I have a gasket on standby)
It was also much quicker to do the second time around...
Ready for another 25k. See ya again at 75k, cams. Woo-Hoo!!
Total time will vary depending on many factors. Because I had done it before and had removed the PAIR plumbing last time, it took ~ 3 hours. Most of that was time being anal retntive about vacuuming grit and dirt up before opening the top end up. The actual checking takes maybe a minute or two once you get the valve cover off. I put the trans in 5th gear and use the rear wheel to advance the cam position, that way don't need to remove the timing chain cover unless you need to adjust shims.
) I managed to leave the gasket stuck to the valve cover.The factory shim was 181 and I had to go up one size to 185. So the gap was too large meaning the valve was not opening up enough...breathing is good! To get a little more technical on your buttocks... 0.010" (.254mm) slid in easily but 0.011 (.279mm) would not so I was just outside the top of the spec which is 0.0098" (.25mm). According to my calculations, dropping the clearance down by .04mm (181 to 185) would do the trick...and it did.How much was that shim out? and where did you shim it to? Just curious.
In both times that I've done my checks (no adjusts needed
If it had come off I'd have done exactly what you did. Silicone seal it to the cover.
Thanks. That's what I was looking for. Also, that is an unusual wear pattern. Normally, what wears on a valve is the seat interface, as that is where the unlubricated friction happens. When that happens the clearances get tighter, not looser. If I found a valve whose clearance was growing I'd suspect some sort of carbon build-up might be occurring on the seat face. You might want to do a compression check on your engine and compare #3 to the others. Of course this is assuming that everything was properly in spec when originally assembled. At least you know what the clearances are now and can compare in another 25k miles.
Actually, this is the industry standard way to mount a valve cover gasket. It's done this way on most automotive engines that have profile type gaskets too. For one thing, it's a lot easier to fiddle with the gasket getting it seated in the groove on a work bench than it is inside the engine compartment. And, as you figured out, it's pretty easy to make it stick in place with a little goo of some type.
I believe that the valve in question on my bike was out of spec from the factory. Because if there was some carbon build up on that valve, why not the other one in that cylinder (or all 4 for that matter)? I checked the shims (both the one I took out of the bike and the one I put in) with my digital caliper and both were spot on. The shims don't wear much if at all. In fact, the shop usually takes them in on trade and reuses the ones they get in. Wear on the shim would of course also cause a loose situation. Obviously the cam is not wearing on the non lobe portion. That leaves wear on the bucket...unlikely, or the end of the valve stem, also seems unlikely. The only conclusion I can reach is that you are correct, that it could be a carbon build up. However since there was only one out in that cylinder, I'm inclined to think it was out of spec from the factory. Helps me sleep better at night.
Yeaaaah, the old magnet trick. They told me about that at the dealer when I went in to get the new shim. I was bitching about how hard it was to get the damn bucket out and they laughed at me and said, we just use a magnet!
