Hello everyone, I am doing the big service and currently measuring the clearances, the bike has 26000km. The closing clearances are on both cylinders within spec (0,05-0,10 both for In & Ex), but the opening ones are completely out of spec (0,13-0,18 both for In & Ex). Three out of 4 are 0.06 and one 0,07 on both cylinders... weird, isn't it? It is the first service, no one else has touch it so far... Usually valve clearances tend to open and note to close. Seems like it came out like this from the factory or the clearances that the manual suggests are crap. Anyone else here with a similar experience? Or shall I go on and order thinner shims to bring them within spec? Cheers, Panos
Hi. I’m new to Ducati but been around bikes a bit. In days of old, clearances did indeed tend to open with mileage. These days with less friction wear to increase gaps I think the valves tend to sit into the seats and close the clearances. Particular if your beating on the engine. This was certainly the case with the big KTM travel bikes I had from new. Once they were set properly at first service interval I found they held pretty constant for many miles not needing adjusting again till around 40 k hope this helps.
@Treadlighty is correct IME, as the valve wears into its seat and as the c-ring closing shim retainers get ever so slightly squished the entire valve stem (and shims) move slightly upwards into the head causing a reduction in opening clearances.
To be honest I did not check the c-rings... so I will replace all of them and re-check the clearances. I keep you posted. Thank you guys!
You don’t need to replace the c-rings if they’re not broken but you do need to make sure they go back on the valve stem they came off and the same way up otherwise it will have a knock on effect on your measurements and replacement shim, although it should only affect the closing shim clearance really. As you’re not changing any closing shims you should be ok.
Different engine I know, but changing the half rings for new ones put all the closers back into spec on my panigale
Since the engine is open, I will replace all of them with new ones and measure it from scratch; and then replace any shims if needed; I want this think to last till the next service;
Once you’ve done this service you’ll probably find that at the next one they’re mostly all in spec still, the valves won’t seat home any further than they have already. There’s always exceptions though.
