Valve clearance stability Q? Anyone grind a shim?

[andmoon]

My 1st valve adjustment and I am thinking of sanding down a shim.

Do they really need checking every 4K?
(my vfr has not needed adjustment post 600 mile check)


I do not mind the adjusting but the running around for new shims is a real pain.

If the clearances do change almost every valve check interval, my new to me 83 850 and I are not going to get along too well.

[hikermikem]

Valve clearances do get tighter with each subsequent check, but usually you can swap shims between other cylinders & only end up having to a get a couple "new" shims at each check.

I would not sand them down - the clearances are quite small & I doubt you could sand them that accurately.

Best bet is to buy a some smaller sized sizes up front, after you inventory what you have now & then figure out which sizes you will need next.

Z1 sells them for about $5 each...

[TheCafeKid]

My 1st valve adjustment and I am thinking of sanding down a shim.

Do they really need checking every 4K?
(my vfr has not needed adjustment post 600 mile check)


I do not mind the adjusting but the running around for new shims is a real pain.

If the clearances do change almost every valve check interval, my new to me 83 850 and I are not going to get along too well.

They do get tighter with age...But that doesnt mean that EVERY 4k they're all going to need changed. You may only need to change a couple this time, and maybe next time or the time after that, change a couple you didnt change the first time...etc.

[jjmaag]

You can try to sand it all you want, but you will be lucky to even scratch the surface. The shims are very hard. Join the GSR shim club.

[Nessism]

It's possible to sand down a shim using wet dry sandpaper but you will be there a while. If you go this route I recommend using a micrometer to measure the shim in various locations to make sure it's flat. Ordering up an intelegent stock from Z1 is far easier and/or look up Ray and join the Shim Club.

[robertbarr]

If the clearances do change almost every valve check interval, my new to me 83 850 and I are not going to get along too well.

Then perhaps you should shop for a bike with hydraulic followers, like the Nighthawk in my sig. Your only other choices are screw adjustment and shim, and neither is 'set and forget'.

Actually, obtaining and manipulating shims is the easy part. Plenty of people, including me, prefer the shim / bucket arrangement over the screw adjusters that you'd find on a bike like the Bandit in my sig. What I dislike about the GS-style engines is wrestling with the cam cover and cleaning the gasket surface. Other than that, valve adjustment is a piece of cake.

It's very common for new owners to spend much more time & energy reading up on the procedure than actually doing it. After the first time, it's really just an acceptable nuisance. With a replaceable gasket (which I've never tried, so I can't comment), even that part of the job is history.

After the first time you do it:

1) You'll be familiar with how easy it is, and
2) Your clearances will be more stable, so you'll have to swap or change just a few shims.

Relax! The water's fine.

[Steve]

You can try to sand it all you want, but you will be lucky to even scratch the surface. The shims are very hard. Join the GSR shim club.

Quoting Paul Harvey, "And now for the rest of the story."

The GSR shim club was started by a guy who had access to a machine that could grind down the thickness of a shim.

It appears to be doing well, but I do not know the details on how the club works. Because of the number of bikes in my garage and the proximity of other GSR members with several bikes (TheCafeKid, N1Elkyfan, Dogma, Buckeyemike and others), I have chosen to maintain my own stock of shims. New shims are available from Z1 for $5.28 each.

That being said, yes, the clearances do change with use. However, they are more likely to change in the first few thousand miles, then will take a 'set' and not change much for quite a while. We got my wife's '82 850L several years ago with about 41,000 miles on it. I had to change several shims due to lack of maintenance by previous owners (no surprise there), but in the last 20,000 or so miles, I think I have only had to change 3 shims.

It helps if you have a means to track your clearances and shims at each adjustment, and, oh my, I just happen to have such a tracking tool available.
Just look at the last part of my sig for info.

.