749 Belt Change Removed belts, now how do I ensure that I get to correct belt timing? - Ducati.ms

Darkness · Apr 10th, 2007, 8:59 am

Hi,

I've removed the belts on my 749. Now how do I reset the timing as the cam lobs have moved (or do I have to do this?) I can find the horizontal cylinder TDC mark on the crank, but how do I ensure that each of the cams are set to the correct position prior to re-installing the belts? Are there marks on the head that I follow to align them? I've got the Ducati manual but its not very clear.

Any advice or pictures would be much appreciated.

CCS31 · Apr 10th, 2007, 9:30 am

The cams will / can turn when the belts are removed. As long as the left side & right side lower timing markers are in check, you can simply turn the cam pulley(s) by hand until the timing-mark on the pulley(s) line up with the timing-mark on the head. Then, put the new belt on.

Dark_Daddy · Apr 10th, 2007, 9:35 am

I am pretty sure that they set timing on the Testastretta belts by use of a Mathsis because the timing is set by sonic waves. You are a braver man than I am for doing it without that tool, which is about 3K by the way. Good luck and I hope you dont rack your engine up.

B_Cebrian · Apr 10th, 2007, 9:38 am

The 749 doesn't have timing marks on the cam wheels. Except for the Ducati special tool to align the cams the only way I know to do it is to make my own marks on the cam wheels, before removing the old belts, to re-align when I put the new ones back on. You might be stuck with having to take it down to your dealer and have them install the belts then finish the rest of the service yourself. Sorry I can't be much help here. Hope someone else has a better idea.

galaxy · Apr 10th, 2007, 12:58 pm

Quote:

Originally Posted by B_Cebrian

The 749 doesn't have timing marks on the cam wheels. Except for the Ducati special tool to align the cams the only way I know to do it is to make my own marks on the cam wheels, before removing the old belts, to re-align when I put the new ones back on. You might be stuck with having to take it down to your dealer and have them install the belts then finish the rest of the service yourself. Sorry I can't be much help here. Hope someone else has a better idea.

Sorry, but +1 to this. There are marks on the cams but they make no sense. I'm sure someone could look at their motor and tell you or walk you through what they see but...Guess that's better than nothing and most likely what I would do if I was in your position. CCS31, the testastrettas do not have timing alignment marks on the heads. You really really should have made your own marks before removal and then done this with the engine already timed with the horizontal cyl on TDC compression stroke (like you said, the timing mark on the crank pulley) I've done this quite a few times and have no way to talk you through this without looking at a timed motor while I'm doing it.

Scott...I don't know what the heck you are talking about buddy

Think you've been around a few too many sonic waves

Getting the timing like he's talking about is a mechanical action of getting the belts on with the cams "in proper time" for rotation with the crankshaft. He didn't make any marks where each fall in place with each other and now something has been turned...not good. Not a big deal at all, but not good if you don't know where they go.

level7 · Apr 10th, 2007, 3:28 pm

I hope you made your marks BEFORE you removed the belts! Otherwise, i think you're screwed.

On my Teststretta (998) there are no marks (that make sense) so you have to make your own marks. It's not hard if you preserve everything by making your marks. There is a special Ducati tool, a key almost, that locks down the cams so you don't need reference marks, I believe this is why there are no marks on the case.

As far as the "sonic" dohickey, there is a tool that hooks up to the Mathisis (sp) that measures the frequency of the belts when plucked to determine optimum belt tension. It's a very nice to have but you can get by without one.

I just took measurements of the tensioners and reset them to original measurements when tensioning the belts.

I check the belts after a few miles and no noticeable belt dust accumulated to indicate I did something wrong.

At my 6k service the shop checked my belts at my request and they made no adjustments.

You really need to buy the shop manual and LT Snyders Ducati maintenance book. Arm yourself with knowledge or have a high limit credit card

EDIT: I just read you have the shop manual...it's pretty vauge only because they use the special tools

That's why I have the LT Snyder book. It gives the "backyard mechanic" point of view.

Unless someone can easily get you back to where you were in terms of the cams, I would take it to the shop. If the cam is reset wrong, you may bend your valves and mess up your heads, hence the need for the high limit credit card

.

You might as well have them degree your cams while you're there...

Good luck.

Darkness · Apr 11th, 2007, 3:51 am

So basically, if you tear down the head, you cannot set the cams to any default factory setting by using a timing mark already ingrained on the engine. So instead you have to get out your lift gauge and other tools and do each set of cams individually? And if you bump the roller, what happens, do you start again?

Correct me if I'm wrong, but that has to be one of the dumbest arrangements. Talk about a round about way of accomplishing a simple task like a belt change.

Surely, it's not that difficult to set the timing back to factory settings?

mackgoo · Apr 11th, 2007, 7:57 am

If you could get a dial on there you could get the cams correct. Do you have a way of getting a dial on?
I have a copy of the shop manual, I could E mail you a copy. Unfortunately it would take a few days to get it to you. I could send it thurs morning. It's for a 999 but the basics are the same. you would need the 749 specifics.

Dark_Daddy · Apr 11th, 2007, 8:24 am

I have a link to a PDF full shop manual, PM me if you want it. its for 05 749 bikes but its the same in regards to 06's

jhord · Apr 11th, 2007, 8:51 am

The Torx head screws on the pulleys can be used for alignment purposes, but unfortunately I don't have any pics of what it looks like, have a Testa onhand or can explain it.

I would head to the local dealer and have them installed, because it could get expensive very quickly if you don't get them on right.