Removing ST3 head - Ducati.ms

Corma · Nov 22nd, 2011, 11:27 am

Hi all, a timing belt broke on my vertical (rear) cylinder last week and I am doing the autopsy...

Should have replaced belts last winter when I ahd it open. I figured I had 2k more miles to go so I would do it this winter. Lesson learned - always replace belts every 2 years as recommended. You can't tell by looking at them.

I am reaching out as I have never taken off the head before. I am doing this in frame if possible.

1. Do I need a special tool to remove the head nuts? They are star shaped, and I get some wiggle with a closed end wrench. Don't want to booger them.

2. I have the exhaust nuts off to remove the pipe. Do I need to disconnect the pipe from the exhaust system to get enough room to remove the head?

3 Airbox removal looks like a project, too

Thanks for any and all help .

**Gearbox** · Nov 22nd, 2011, 12:08 pm

Sorry to hear of your woes and good luck with the investigations.
Cant help you with the information you need but it is a serious reminder to us all of the risks of ignoring the replacement schedule set out and I , for one , thank you for your posting.

va duc · Nov 22nd, 2011, 12:16 pm

You can pick up a proper head nut removal tool here:
Tool Product Gallery

I am not sure you can get the vertical head off in the frame, I believe there will be clearance issues. You will probably need a few new o rings and such that fit between the head and cylinder, also you will need to drain the coolant and possibly the oil.
Best to remove the exhaust entirely, and it is easier to fit back up that way.

tonered · Nov 22nd, 2011, 12:49 pm

I just did a vert head removal on my ST4 a couple months ago. The engine stayed in the frame. The only clearance issues were getting the exhaust and intake nuts off. If you have those freed up, then the rest is cake walk. I had to grind down the head nut tool to work, but it did work very well.

For me, I had to remove the whole header (horiz and vert) to get the vert header into a good position. The coolant was swapped, but oil shouldn't be a problem, at least for me it wasn't. Just the one feed line had to come off.

Good luck.

Just to clarify, you had belts that were more than 2yrs old with more than 12k on them? They were Duc brand or CA Cycleworks? This is important info for general knowledge. Sorry that it happened to you.

Have a good one.

va duc · Nov 22nd, 2011, 12:54 pm

Quote:

Originally Posted by tonered

Just to clarify, you had belts that were more than 2yrs old with more than 12k on them? They were Duc brand or CA Cycleworks? This is important info for general knowledge. Sorry that it happened to you.

Have a good one.

Good question Tony, I will be watching for the response, I put 10,000 miles on my belts this year after changing them last winter.

ducat · Nov 22nd, 2011, 1:14 pm

You can make an excellent tool from a 14mm combo wrench. You will have to grind down the box end to about 1/8 thickness and then use a torch to heat and bend it to a U shape then weld on an old socket to the top. took me about 1/2 hour. There is only a rubberized head gasket between the cyl and head, no O rings. Make sure you do not disturb the cylinder base gasket seal when lifting the head off. re-torque after one heat cycle after you get it back together.

what broke now · Nov 22nd, 2011, 3:22 pm

"3 Airbox removal looks like a project, too"

IIRC, there are two internal phillips screws inside the box near the front, a drain tube that must be removed, and two mushroom-head studs at the back. The box simply lifts off the mushroom studs once the screws in front are out. The two velocity stacks aboard the throttle bodies mount camera lens-bayonet style and rotate off after releasing a strap retainer.

ducat · Nov 22nd, 2011, 3:52 pm

ST3 airbox removal requires 1 allen bolt up under the front bottom that you can get to without removing the radiator, remove the bolt holding the top of the coil support to airbox at the right rear edge, unscrew the mounting rod from the airbox left rear corner. Do not forget to remove front drain hose and rear vent hose from air box. half turn CCW both velocity stacks (note:front longer than the rear) and pull out.

what broke now · Nov 22nd, 2011, 4:16 pm

Ahhh...thanks for the correction, I was thinking st3 & st4 both the same, not so.

Corma · Nov 22nd, 2011, 6:19 pm

Group,

Many Thanks for your help.The ST3 is a 2005 that I purchased new latein the year. The bike has a little over 10K miles on it.

The belts are original equipment looks like they have white writing on 'em and what looks like fine wire or filaments inside. The replacements I got from CA cycleworks last year, have Ducati packaging and white writing on them, too.