<-=- Club Bevel Heaven -=->

Hi, I had to re-seat the valves on my Darmah and now the clearance between the opening rocker arm and shim has changed. Intake valve now .003 and exhaust virtually nil (haven't checked other head yet). Can I sand down the shim myself, and if so any pointers on best technique and what # grit to use? Also, I keep reading that either O-rings in valve guides or seals or both will need to be replaced. I never came across either taking valves out. Is that possible? It's a '79 Darmah. All comments appreciated. Thanks.

sd900 wrote:Can I sand down the shim myself, and if so any pointers on best technique and what # grit to use?

Yes, with care: Use a double-sided medium/fine oilstone and circulate the shim in a figure of 8 pattern. Alternatively, if you know what you're doing, you can touch-grind them on the edge of a grind stone. But I wouldn't recommend it.

sd900 wrote:Also, I keep reading that either the O-rings in the valve guides or the seals, or both, will need to be replaced. I never came across either taking valves out. Is that possible? It's a '79 Darmah.

Yes. Either they've been lost or someone has replaced the guides with after-market ones that don't use a seal. A '79 bike should have the guides that take an internal seal (part# 0400.17.030). From 1980 on, the guides were modified to take an external seal (part# 0799.92.395).

Note: if you fit the later type of guide, the underside of the closing rocker may have to be relieved slightly. Otherwise it can crush and tear the seal.

HTH

Craig

Keep in mind you will likely have to reshim the closer too. The spec. was originally nil. but the modern consensus is about .0015-.002". Many times a loose ish closer can be brought into spec by flipping the retainers over.They wear at the contact point on the shim and flipping them presents a new surface to bear on the shim. You can sand them like the openers if you need a bit more clearance but keep things as square as possible when sanding. In time you will develop the callous/raw meat/cramped/fingertips that identify you as a real Ducati owner.[Kind of a secret ID amoung the real Ducatisti]

wdietz186 wrote:Many times a loose ish closer can be brought into spec by flipping the retainers over.They wear at the contact point on the shim and flipping them presents a new surface to bear on the shim.

Now that I didn't know, Bill. Ta.

Many thanks. wdietz186, are the retainers you mention the small c-shaped colletts that hold the closing shims in place?

Yes they are. They are also used in most of the beltdrive models and are pretty cheap so if you drop or lose one it isn't the end of the world. If they are worn on both sides new ones will sometimes pull you back to spec. It all depends how obsessive you get about it,but it does help to have some extras on hand.