2007 ST3 valve adjust - Ducati.ms

Craig in Texas · Jan 28th, 2012, 8:27 pm

I'm in the process of doing my 15,000 mi valves/belt service and had some complications that I'm hoping someone may have seen before. I have the belts off and so can roatate the cams at will. It seem that no matter where the cam is rotated the horizontal exhaust rocker will not slide over to allow removal of the shims. I got around this today by pulling the rocker shaft out. This is not really a big deal but it adds to the time and complication. One thing I learned is that while the left side cam bearing cover is off (removed to extract rocker shaft) you cannot get accurate clearance readings because the cam can move a bit since it's only supported on one end. This leads to lots of monkey motion of installing/removing the cover.

Now I am seeing the same thing on the horizontal left intake. I cannot seem to get the rocker to slide over no matter where I posiition the cam.

Has anybody else seem this before?

Thanks for any ideas. By the way since all my clearances were too small I am using Desmotimes clearances and sanding down the shims to get the proper clearances.

DuckMan · Jan 28th, 2012, 8:49 pm

I always have to apply side pressure to the rocker and rotate the cam slowly until it hits the slot. I usually have more trouble moving it back over valve.

stryder · Jan 29th, 2012, 8:53 am

Like your favorite woman, there are sweet spots, and you must find them.

Since you have the belts off, you can easily rotate the cams. Re exhaust opener rockers: With some outward pressure on the rocker arm from one hand, slowly rotate the cam with he other. (CCW on the horizontal IIRC) When the cam hits the sweet spot, the rocker will slide off just as slick as snot. Slidng it back on to the measure the gap may also require finding the sweet spot again, but both H and V opener exhaust rockers can be slid off their valves The intake opener rockers can be slid off, right hand side I believe is the problem on the V cylinder, with the exhaust opener off first. Just like you would with your favorite woman, keep at it, and get familiar with the "feel" of the sweet spots.

Good luck.

mlukason · Jan 29th, 2012, 12:19 pm

I've left the belts on and turned the engine with the tool. Next time I'm removing the belts...should be a lot easier.

My ST3 also has a rocker that is very difficult to find the "sweet spot." Can be very frustrating but it slides over eventually. Hopefully you'll find you won't have to remove the shaft...that's sounds like a pain!

Craig in Texas · Jan 29th, 2012, 8:04 pm

I had another go at it this morning and everything is good now. I guess I just needed to take my own advice that I always tell my son. If you get to what seems like a dead end while working on something, sleep on it and you will usually solve it the next day. Steady pressure while rotating the cam seem to be the key.

Upon inspection all my clearances were less than spec. The smallest feeler I have is a .0015" and most of the clearances were less than that. The engine now runs noticeably smoother, especially at low rpm.

jduke · Feb 16th, 2012, 2:37 pm

Quote:

Originally Posted by Craig in Texas

I had another go at it this morning and everything is good now. I guess I just needed to take my own advice that I always tell my son. If you get to what seems like a dead end while working on something, sleep on it and you will usually solve it the next day. Steady pressure while rotating the cam seem to be the key.

Upon inspection all my clearances were less than spec. The smallest feeler I have is a .0015" and most of the clearances were less than that. The engine now runs noticeably smoother, especially at low rpm.

I agree. I've been working on a bike and will run into a wall. A good nights sleep seems to open new opportunities. But what's bad is when the "fix" wakes you up in the middle of the night. Can't go back to sleep but too early to get up....