I checked my valve clearances yesterday and two of them were tight  I was wondering if there would be any harm in removing the ones I have in there, sanding them down, (using sandpaper over glass to keep it flat), polishing them and re-installing them. Has anyone done this? If so were your results good?

I've heard of people doing this.  They recommend the factory surface facing the cam just to be sure.  But personally, I wouldn't do it to save five or even ten bucks.

Hi there,
Honestly, that's not a great idea. 
Just get the proper shims as you ever need them and do it properly.
It's not often that a shim is ever needed anyway.
Are you trying to save $8 once ever several years?
The shims would be very hard to sand, hard to keep flat and I would bet that the abrasion you cause could increase wear on the cam lobes because the shim is no longer as smooth.
This just does not sound like a good idea.
That's just my opinion, based on 32 years of motorcycling and wrenching on my own bikes.
Best wishes,
Todd

Sounds like you need a hobby.   

Silicon Carbide sandpaper will work, an oilstone would be better.  Cut in with 120 or so and work your way up to 600.  Make sure to lap in a circular motion and lap the bucket side of the shim only.

A friend with a surface grinder would be significantly faster.   

Yeah, I was planning on sanding the side opposite the cam lobe, and since i only need to remove .001" or .002" I don't think it'll take to long. I'm not trying to save the money but the hassle of tearing the thing appart and then finding a way down to a bike shop (bike is main mode of transportation) and hoping that they have a propper shim. If I could buy the propper shim ahead of time I would do that but that isn't the case.

Again, has anyone ever done this? and if so did they stay in adjustment as well as factory shims?

Quote from: GeeP on February 22, 2007, 03:41:59 PM
.....
A friend with a surface grinder would be significantly faster.   

We have 9 of them at work. 

Quote from: Trwhouse on February 22, 2007, 03:35:12 PM
It's not often that a shim is ever needed anyway.
Are you trying to save $8 once ever several years?

Well that might be true of intake valves, but on the exhaust valves after the milage picked up I was changing them a couple times a year on my 97 GS.  Depends on your annual milage.  Seems to be the same pattern developing on the 02 GS now.

My valve checking/shimming record for 120k miles on the two GS's:

http://img.photobucket.com/albums/v443/jcp8832/valveclearances.jpg

I agree on replacing the shims rather than grinding them down even at the $13 each my local dealer is charging now.  I was considering grinding one down for a 97 exhaust valve that was down to the min 215 shim thickness though, but I parked it at 80k miles and am no longer using it.

I have a tight exhaust on the left cyl and a tight intake on the right cylinder. If you guys really think it's a really bad idea, I'll just wait untill I can get Kerry's valve adjusting kit. I'll probally try to minimize the millage on the thing in the meantime. I usually put arround 10,000 miles on it per year.

Quote from: ducati_nolan on February 22, 2007, 04:01:21 PM
Yeah, I was planning on sanding the side opposite the cam lobe, and since i only need to remove .001" or .002" I don't think it'll take to long. I'm not trying to save the money but the hassle of tearing the thing appart and then finding a way down to a bike shop (bike is main mode of transportation) and hoping that they have a propper shim. If I could buy the propper shim ahead of time I would do that but that isn't the case.

Again, has anyone ever done this? and if so did they stay in adjustment as well as factory shims?

Can you spin the shim in the bucket at all?  If there is any clearance, your best bet is to wait.  I rode around with zero clearance for a couple of days before I was able to track down the right size shims.  I take that back, I rode around with zero clearance for a long time, I only was aware of the fact that I had zero clearance for a couple of days.  Call all the shops in or around town, and somone might have some shims. 

What sizes do you need?

I don't know what sizes I need yet, I don't have the tool to pull them. It looks like the wait for Kerry's kit shouldn't be too long so I'll probally wait. I couldn't get my .0015 feeler in there and I could rotate the buckets but not as easilly as the others with .002" clearance, so I don't really have any clearance.

My original plan was to make a removal tool, and sand down the original shims, but I'll probally just wait now. 

Ahh, main mode of transport...  Now it makes sense.   

It's not a bad idea, hand lapping is done all the time.  Be sure that you lap on a flat surface, go slow, don't push hard, use water to keep the paper from loading, and use a circular motion.  Place two fingers on top of the shim to apply pressure.  Do not try to grip it with thumb and index finger, the pressure distribution is not even and will destroy the parallelism of the shim.  Rotate the shim relative to your fingers every 30 seconds or so, less during cutting.  The pressure of your fingers will tend to rock the shim on the paper, you want to distribute the error.

Tip:  Rubber cement the silicon carbide sandpaper to the glass using a small roller to remove the air bubbles.  Doing so will keep the paper flat.   

Be sure to turn the engine through two complete revolutions to seat the shim before re-checking the clearance. 

If I could turn the valve bucket with my finger tip, I'd record it .001" clearance and generally let it go till next time.  I could only measure down to .002" with my feelers and the valve spec is .001-.003.  If the bucket was tight and couldn't be turned with the finger tip, I replaced the shim.

Are your valves actually tight with no clearance and being held open a bit or by tight do you mean they are just below minimum and the bucket is still free?  A valve that is actually tight and being held open will cause the engine to run rough on start up for a brief while till the engine warms up some.  Valve clearances increase considerably as the engine warms and it smooths out as soon as the valves seat and seal.

If you can turn the buckets with your finger then you can check your shim sizes and button it up and get smaller shims to put in later. I never use the tool, I change shims with a couple of screwdrivers.  Pry the bucket down with one and place another turned vertically between the edge of the bucket outside the shim and the camshaft.  A screwdriver with a 1/4" approx wide blade is about right.

Revision: saw your post that your "tight" buckets will rotate with finger, I'd run it a while that way and in fact have done so.  Your bike, your choice.   

I couldn't read any marking on the shims without removing them, so I don't know what size to get. I can rotate the shims/buckets with my finger, but they don't rotate as easilly as the two that have about .0015" so I would say that there is no clearance. It still runs okay but I think it may be lacking a little power, and I've cleaned the carbs and changed the plugs so.... yeah, I need to adjust them.

If I don't get a response on the post for Kerry's west coast valve adjusting kit by tomorrow evening, I'll try and pull the shims out with screwdrivers or a homemade tool and sand them down. I was thinking of making a tool with a shape like the "correct" tool but make it out of some scrap hardwood  seriously. I think it'll be easy enough to make and should work, if not I'll figure something out.

If you can rotate the bucket, then you do have some clearance.  That means, if you can rotate the bucket, there is no need to sand down your current shims.  I, and many others, constitute zero clearance as being unable to rotate the bucket.  Call every dealer in town and track down a shim tool.  This tool is important to have.  I've taken shims out without the tool, just to see if I could do it, and it's not too difficult.  Magnet and screwdrivers will get the job done.  The shim tool will get it done more quickly.

There are several reasons you shouldn't sand down those shims if you don't have to. 
If you sand down those shims, you can't ever trade them in for new shims.  My dealer will let me trade in old shims free of charge.  I assume most dealers will ?

If you mess up on sanding, you can mess up your cam lobes.    No bueno.

Remember, if you can rotate the bucket, you've got some clearance, and you can wait for a few days for new shims, and or a shim tool.  Get those things pulled out and post what sizes you need if you can't find them locally.  Someone will hook you up.

nolan just take your shims to the dealer.  They'll probably trade you even for what you need.