rebelpacket.net unsticking stuck collets

We're human. We all make mistakes. In my case, I installed my MBP Collets, some how managed to do my math wrong, and ended up with the closing shims too tight. (Since then, I triple-check my measurements). But I put it all back together, started it up, and was suprised when it was running funny.

Well, of course it was running rough. There was negative clearance on the closing rocker arms made it almost impossible to rotate the cam pulley. I was lucky that nothing broke, seized or worse. Hey, we all make mistakes, like I said. Too little coffee, and too eager to ride can be disasterous.
So I tried to get the collets off. No dice. I gave the closing shim a few taps, to no avail. My mistake had pressed the closing shim hard enough onto the collet, that it was good 'n stuck. After talking with Chris Kelley, and Guy Martin of MBP Ducati, we found a solution. Here is what I did to get the collets off, without any damage to the valves, or the collets themselves.

1. - To do this, you have to take off the head (or heads if both cylinders have stuck collets). This isnt really a big deal, just make sure you loosen the nuts in a criss-cross pattern. I usually spray some WD-40 on the nuts, let it sit for as long as it takes to make a pot of coffee, and then go at it. If you have the special ducati tool to take off and on the head nuts, then your good. If you dont have the tool, you can make one, with a 15mm ring-wrench, and a 1/2" socket extension welded 83mm from the center of the ring-wrench. If you don't have either of these, or your waiting for one to ship to your house, you can get it off with a standard 15mm ring-wrench. But it'll take some effort.

2. - Now here comes the the difficult part. Find your dogs tennis ball. Chase your dog all the way around the house until she gives it up, apologize to her, and cut it in half. Your dog will probrobly growl at you, or poop in your shoes for destroying her toy, but you need to get your toy back together. Alternatively, if you don't to deprive your dog of its tennis ball, you can go out and buy one.

3. - Now, your probrobly thinking. "A ball? What does a ball have to do with valves?" Well, thats what I said too, when Guy Martin suggested using it. But after some thought, it all made sense. The problem with trying to "un-stick" the collets, is the fact that you dont have a way to hold the valve in place so you can hammer the closing shim off the collets. But how do you do that, without bending a valve? Obviously, a tennis ball. It is strong enough, that it will actually hold the valve in place, but soft enough, that it'll bend and contort, way before the stainless-steel valve will. Props to Guy for his very effective "Out of the box" thinking.

The next step, was to simply get the opening shim off, and slide the opening rocker arm out of the way. Then I rotated the cam pulley until the detent for the closing rocker arm came around, and I could push the arm down. (Like you would do if you were changing the closing shim in a valve adjustment). As you can see, the half of the ball fits into the combustion chamber pretty nicely. Seats well up against each valve. It raises the head up a little bit off your work area. I found it was hard to keep it from wobbling around while I was trying to pound off the shim. Easy solution, was to put a old timing belt around the base of the head. It was just enough to stabilize the head, without lifting it up off the tennis ball. If you press against the valve stem with your finger, you'll notice that it isnt going anywhere.

4. - Now, here comes the tricky part. For this, I used a pencil flat-blade screwdriver. Its small enough that it'll fit on the edge of the shim, but solid enough to take the blows from the hammer I used to pound off my shims. The way I found to work best, is to start by tapping with moderate force, all around the upper lip of the shim, taking care not to hit the collets. On the intake valve, I gave it some moderate taps around the edge, followed by two square blows, and the collets popped free. The exhaust valve on the vertical cylinder wasn't so understanding...

5. - I had to put some time in on the exhaust valve. I just kept pounding away, checking every couple of hits to see if the collets had broken free. Eventually brute force won, over my own stupidity, and the collets came free. I was worried that I might deform the valve in some way. So when I had all the collets off all the valves, I checked them for runout on my v blocks. Perfect! No troubles. I checked the valve guides as well, and they were within spec.

Granted, I can't be responsible for what you do. This isn't exactly "standard" procedure. But if you have any questions, please feel free to Contact me. 99% of the time, a "stuck" collet, can be freed with a light tap on the closing shim. But there is always that 1%...