Hi all-
Working on my first valve inspection/adjustment and wanted to pick your brains closer clearances. I did search and tried to ensure that there was no definitive answer on this topic, but if I missed something my apologies in advance.
The bike has 7,500 miles on it and no prior valve adjustments.
I put the engine at TDC on the vertical cylinder on the compression stroke and, unsurprisingly, found that the openers were tight on the intake and exhaust valves, and the closers were loose. I have adjusted these issues.
Interestingly, after putting the horizontal cylinder at TDC on compression, the results for the horizontal clearances were different. Openers for both intake and exhaust are just over 0.1mm (so just about perfect according to Lt Snyder). The closers, however, have close to, if not, zero clearance. I can rotate the closer shims (unloaded), but it is not easy.
I am concerned that I may be doing something wrong due to the differences in measurements on the vertical vs. the horizontal cylinder. Most specifically, I am surprised to find the closers on the horizontal cylinder at almost zero clearance.
Two questions:
1) Is it abnormal to find the horizontal cylinder's clearances seemingly in spec after 7500 miles when all shims required replacement on the vertical cylinder?
2) I barely get any increase in clearance when I load the rocker arm on the horizontal cylinder, and therefore believe that my closer clearances are at close to zero, if not at zero. I assumed they would be loose. I am ok with reassembling as is, and giving Ducati a remote "air five" for assembling the horizontal so well that it did not need any adjustment, but am concerned that the closers may be too tight, and may damage the cam if left as is.
Side note- I am currently uncomfortable with taking the belts off and spinning the cams independently of the crank to check for binding, because I fear improper reassembly and the resulting bent valves. However, I could be talked into trying this if the prevailing wisdom suggests that this is the best course of action.
Thanks in advance for any help that you can provide.
1/ nothing is abnormal
2/ assume nothing, just work with the reality at hand.
I always remove belts. can't imagine trying to do it with the belts on.
I pull the opening rockers on ds motors (both per cylinder when doing closers), that way you can spin the cam fully as the ds usually get tight on the closers at the very ends of the lobe. a little clearance in the middle may mean tight at the ends.
Thanks Brad. I just wanted to make sure what I found was not abnormal. I appreciate the response.