I'm currently knee deep in my. 796 project... I ask does anyone know how to remove engine valves please? I checked the usual suspects like YouTube and the web but can't find anything relevant ... My 2 valve 2010 cylinder heads are on the bench but as I say no luck with info.. Haynes don't make a manual for my particular bike...
It's actually very easy. Remove the valve covers, which you've probably already done. Remove the spring clip at side of the opening rocker shaft. Now rotate the cam until the valve is just on the point of opening. The rocker should slide along the shaft uncovering the opening shim on the top of the valve. Remove the shim, measure it's size and put it in a zip-lock bag with a note of which valve it is from (eg. horz inlet). Then push down on the closing rocker with a blunt tool, I use a 1/4" drive screwdriver type handle. You will need to rotate the camshaft to the valve fully open position. With the rocker held down you can now slide the closing shim down the valve stem and remove the half rings. Best to use a small magnetic to catch them. then slide off the closing shim. Sometimes they are difficult to get off because if it has been running with too large clearance a burr develops at the groove in the valve stem. You can ease this off with a bit of emery. Remember to put the shim and half rings in the same bag as the opener shim. The valve should now slide out of the guide. Once the rocker is depressed I use a 10mm allen key slipped underneath to hold it there it makes work much easier not having to hold it down against the spring.
Derick What an absolute star you are... Been searching for days trying to find the correct method... Beautifully explained. What I was hoping to do was just take the one valve out, de coke it and then put it back before doing the next one, bagging everything as well. That way I shouldn't get in a muddle.... If I do it that way will I need to check adjustments again? or as I'm replacing what I'm taking out, eg shims, will I not need too.. Thank you for being so helpful, I was, many years ago a car mechanic, so I've still got a little idea left, obv though it was all valve springs and collets for me.. So this is very new, enjoying it though.. Thanks again.. Best regards N@@DS
You should always recheck clearances even if they were spot-on before, could be a sign of something not put back right? Plus if you're cleaning the head & valves it would be wise to lap the valves into the head once cleaned, this and removing the carbon build up might mean the valve seats a bit deeper, so altering the clearance. Checking the clearances is straightforward and if you can remove the heads & valves then using feeler gauges should be easy enough.
Yes good point... Would be good to learn how to check and adjust valve clearances as well... Never too old to learn eh ! N@@DS
Yes, you will definitely need to re-check the clearances. Re-seating the valves will close the closer gaps slightly and increase the opening clearances by the same amount. The shims come in .05mm (.002") increments. If the closers are .05mm or less, leave them alone, if they are more than .05mm go to the next size up. Openers are pretty straight forward, just go for whatever size brings it within spec.
Speaking as someone who has no experience with doing this to a Ducati.... (last time was a Briggs & Stratton...) am I being stupid or won't lapping the valves in reduce the opening clearance slightly, because the valve will sit margianly deeper in the head? Also, is it possible to adjust shims by marginal amounts by using wet-and-dry or similar? If it is possible, is it a bad idea? I seem to remember seeing this suggested somewhere.
Oops! Red face time. You are absolutely correct; the openers will reduce and the closers increase. I must remember to engage my brain before typing. Yes you can adjust shims by using wet & dry but there is the danger of reducing them unevenly and it also takes a hell of a long time. I prefer to adjust them to within the specified range of clearance, preferably as near as possible to spot on.
Yes, I have done this to fine tune small changes but you'll probably still need some new shims, unless you can somehow put back onto the opposing shim the material that you remove...
Success .... Valves are out... Those little keepers is there a correct way up to fitting those? Thanks for all your help, decioke now then valve grinding followed by adjustment... I hope..
That valve looks quite good. It's not going to need much of a grind. The keepers develop tiny ridges on them where they contact the groove in the valve and the closing shim, you can see them if you look very closely. Re-fitting them the other way up will probably alter the clearance slightly. Many people will fit new keepers every time. Here's some info that may assist you in setting the valve clearances. Guide to adjusting Desmo valves.
