What is needed, other than the appropriate size shim to adjust the valve clearance? Does the shim somehow snap into the valve tappet without any special tools required? I assume only one shim of the appropriate size is used and not multiple shims per valve? I assume you don't have to remove the valve springs to swap out the shims? What is the best setting for intake and exhaust valve clearance? The service manual just gives a range 0.004" to 0.006" (0.1mm to 0.15mm) for both intake and exhaust. It looks like some shims are available in 0.05mm increments, other values in 0.1mm increments, with values from 2.1mm to 2.9mm. Does anyone know about what size is nominal? I would guess somewhere in the middle of this range. I read in the www.f650.com message board that the camshaft bridge needs to be torqued very carefully and very accurately to 10 NM, otherwise the camshafts may not rotate freely. Also, there is mention of an allen key to move the crankshaft into TDC setting as well as a crankshaft locking bolt to secure the crankshaft. By allen key do they mean a standard metric allen head tool or something special I need to order? Also, it is not clear to me where this allen key is used to adjust the crankshaft and how you know when you are at TDC. Is it necessary to lock the crankshaft with the locking bolt?

I read this about setting valves:

"Further more it has been his and my experience that the engine runs better with the valves on the looser side of the specs than the tighter side, which may account for the extra wear on the cams. You see, if the gaps are tight and as the engine warms up and the cams and valves expand due to the warmth, you then have an even tigher contact with the shims and the cams.

I believe it was Oliver from Germany on the board that was telling us all to set the exhaust valves to .15 mm to .20 mm according to a service bulletin by BMW AG to it's German dealers. Some how this information has yet to make it BMW NA and others.

The best numbers to use for adjusting the valves is using a thousands of inch feeler gages. For the exhaust shoot for .007 inches which is .17 mm. For the intake shoot for .005 inches which is .127 mm. This way the clearances aren't tight but no loose either."

And to answer your question... NO I haven't ever adjusted valves before or seen it done. I'm sure it is not that big a deal.

 

ScoobyDFW,

I have adjusted my valves a few times because I got the Woods Stage II kit. The spacers just pop out. Take a pocket knife or something witha sharp point and pick the shim out at those cut outs on each side of the spring barrels. Or a strong magnet will work but the oil under the shims causes the shims to be sucked in the barrels so it can be tricky. As far as clearance goes, Woods Racing told me to gap mine at .006" to .009". So I gapped the intakes at .006" and the exhaust at .009" because the exhaust valves get alot hotter then the intake there for they will grow more which tightens your clearance during normal operating temperatures. To place your engine at top dead center you have to unscrew the plug on the right side of the crankcase to gain access to the allen screw. It takes a metric size (cant remember off hand)and turn the crank clockwise until the two marks on the camshaft sprockets line up horizontally with each other ( - - ) . At this point both cam lobes should be facing away from each other and neither should be touching the valves. At this point you can check your clearance with a set of feeler gauges. As far as the crank set screw goes , I have never bought or used one so you really dont need one. The crank will stay at TDC without the set screw. I see you mentioned the f650 which is a BMW dirtbike which uses the same engine. I got my shims at the BMW motorcycle dealer. They had a box full of them. I suggest your take a micrometer or dial calipers to make your choice because they are all stamped in millimeters. My bike came stock with .094" on the exhaust and .098" on the intake side so measure the ones you have and keep them seperate.

 

Thanks!

 

The cam chain tensioner had me stumped for a couple of minutes. I wasn't sure how I could release the tension w/o removing the gears, then I found the bolt that needs to be removed for this. All my valves are on the tight side. Exhaust is at 0.004" and 0.004", intake is at 0.004" and 0.0025". I don't have a micrometer handy just yet, but all the stock shims looked around 2.3mm thick. Do you think I'll notice a difference once I loosen the valve clearance?

 

Its hard to say Scooby but .0025" in definitally to close. Once the engine warms up you may have no clearence on that one side. When I first ran my DS with the stage II I couldnt really notice a difference from stock and found out later when I re-adjusted my valves that one intake valve was staying open .002" all the time!! Talk about compression loss!!