I have just measured my 906 valve clearances and they all need re-shimming. The closer gaps are 0.08 - 0.1mm, and the opener gaps are all around 0.03 - 0.04mm. I found that I needed to remove the radiator to get at the horizontal inlet valve and even then it was tricky to measure that closer clearance. I am slightly concerned about trying to remove the keepers on the closing shim, particularly on that cylinder. I was considering taking off both cylinder heads so that I could fit the shims on the bench and be able to be confident about the gaps that I have. One of my questions is how easy is it to remove the cylinder heads with the engine still in the frame. I was assuming that once the timing belt is off and the inlet ducts and exhaust pipes are off I should be able to undo the nuts on the heads. I presume I will need to use a ring spanner. Assuming that is the case how do you torque them up on re-fitting. Is this the way to go or should I just struggle and try to replace the shims with the engine still in the frame, making sure that all its orifices are blocked so that no bits of metal drop into the bowels.
Shims. Is there a supplier in Europe/UK. Do the shims have sizes printed on them although I am sure I will have to measure them in case a previous owner has ground them down. I am not overly sure how the opening and closing shims relate to each other. If in my case I fit a larger closing shim, will that also affect the opening gap. Sorry this is a bit rambling but I am normally used to valves with springs. As always any advice is greatly appreciated.

I have never taken the heads off to do valve adjustments unless they have been off already for another reason, although it is much easier to do them on the bench. You should be able to remove the heads with the engine in place but remember you will need to replace the various o-rings at the head joints.
The attached diagram might help to give you a better understanding of how to measure the shims and once you have pushed down the closing rocker insert a 10mm allen key below to prevent it from returning. This willl make it much easier to remove (and replace) the half rings and and closer shim.

Thanks Derek, useful advice, particularly with the Allen key. Also Paso 750. You have both convinced me to leave the head on, which was probably a last resort anyway. Is there any danger of the valve sliding into the cylinder when the halfrings are removed. Still at least I will have a use for that big bag of ear plugs that I bought.
I had read on this site that the opening shims were available from Alfa Romeo, again valuable information.

Looking at the workshop manual it has the clearance as 0.1mm opening and 0.02mm closing. It would appear therefore that the inlet and the exhaust valves have the same gap. As the shims only appear to be available in 0.05mm increments I presume you go for the nearest one to the correct value. Is this correct ?

Having looked at the differing information regarding valve clearances on this site I have decided to aim for:-

opening inlet clearance 0.1mm - 0.12mm
closing inlet clearance 0.02mm - 0.04mm

opening exhaust clearance 0.12mm - 0.15mm
closing exhaust clearance 0.02mm - 0.04mm

Ducati has changed the specs over the years and models. So the clearances you list are a bit higher than original 906 specs but alright. However if possible try to stay closer to the min values.

Thanks Paso 750. The minimum it is, or at least I will try to set them at those values. I am just waiting for my bits to arrive from EMSDUC. I found Mike Guidera really helpful.

G

Just for the record: the distance between the ring and the weld socket nut (special tool for the cilinder head nuts) is not relevant: as long as the torque wrench is attached perpendicular the set torque is correctly applied (physics).

Frank

Hi there , one ( or two ) things Id like to add is that the closing shims clearance is near as dammit zero at 0.01mm ( less than 1/2 a thou ) and in practice this equates to ...............once you have stopped the closing rocker spring having any effect ( 10mm allen key if you like ) is that you should be just able to turn the valve by rotating the stem between thumb and fore finger . This is something you sorta grow into so until you get the hang of it do use feeler gauges. Front pot access is not easy , I just lie down on the ground.
Often the collets will come out in pieces and can look a bit " hammered " round the circumference and just replacing any damaged ones will go a long way to getting the clearance back to spec . The factory ones are crap and a far better option is to use MTB collets ( google em up ) they aint cheap but are good value in the long run . I have noticed that the harder you flog the motor the more attention the valves will require . I used to measure the clearances and then remove and individually bag each shim with its respective clearance and take them to the local Ducati mechanic who would then exchange them for ones that would give me the correct clearance , and charged me 10 bucks a piece. Openers can be ground a wee bit . Opener clearance will tend to close up and closers will go bigger so if you and set the clearance at the best end of the range gives you a bit more "wear " before having to reset them again.
Here is a pic of my cylinder head nut spanner , and clutch tool , cant find one of my closing spring tool thing.
Regards
Hamish

That's MBP collets - Martin Brickwood Performance

Yeah, I get it wrong every time, and fecking spell check don't help coz even when I googled it wrong it shows the correct pic