0.03 - 0-08mm is the recommended range.
But some people run up to 0.10 clearance or slightly more sometimes!
The 650 uses a Shim system, which means you can't just adjust your valves.
You have to buy or swap out shims, which are metal discs and are a preset size in Millimeters.
z1enterprises.com sells shims in singles or sets....GREAT website!
So if you stick a 0.03mm feeler in there, but it barely fits in, this means your clearance is TOO TIGHT..... You will need a smaller shim to create more of a gap so the valve won't be running extremely tight..... 0.03mm is the MINIMUM clearance allowed, which basically means, you DONT wanna be running that low....try to get a shim that puts you somewhere around 0.05 or a tad higher if you can.
Remember, it's better to run Loose than Tight!
Tight valves can absolutely kill these motors!
Okay, to clarify again........so you stick the 0.03 feeler between the shim and came lobe on Intake #1 to measure it, and the 0.03 just barely fits in or feels kinda hard to push thru....well you're at the minimum clearance or worse, you really want to be quite a bit looser than that! Now you pull the Shim out using proper procedure, look at the Shim and it reads 2.65, so you're going to wanna order or swap for a 2.60 shim, which makes the gap more loose, exactly what you want!
(shims have their size printed on the bottom of them, sometimes it's very faded but you can usually read it, but you DO get some that are faded beyond eye sight, so you DEFINITELY want to buy a cheapy Micrometer to measure it........in fact measure all of them just in case! Because you will get 1 or 2 shims that have something like "2.65X".......notice the X? Well the X means that it's slightly larger than 2.65....so hence thats where the micrometer comes in handy, to see what it REALLY is!)
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Steve has a Valve Adjustment spreadsheet that automatically calculates what shim to use. Let me know if you want the spreadsheet.
There's also some tutorials on bass cliffs website that shows how to do the valves.
Here's his main website loaded with tutorials.
http://members.dslextreme.com/users/bikecliff/
Just browse down some, and there's a link that shows how to do valves i believe!
You can buy the Bucket Tappet tool, or just use the zip-tie method.
I couldn't find any damn tappet tools anywhere locally, and had a buncha zip ties laying around, so I used that method......I would never do it any other way after trying that method out!
It takes a try or two to get it right, but once you get it.....you get it!
