Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 851 / 888 > Cambelt not running true

[andya]

Hi,
Just replaced the cambelts on my 888 and on turning the engine over manually to make sure the timing marks are aligned, the belts both run towards the back of the tensioner pulley very close to the barrel.

I've checked the tensioner bearings which are ok and the belt runs true on the idler and the toothed pulleys.

I am turning the engine over clutch anticlockwise, which I presume is correct. The only thing that seems odd is that the face (where the back of the belts touch) of the tensioner pulleys is curved slightly as are the idlers.

What am I missing??

Andy

[nelly]

Check the tensioner pulley mounts haven't unscrewed. When you undo the lock nut to rotate the pulley, you can undo the mounting bolt.
Remove the pulley, and check it's tight. Remove and use loctite for peace of mind.

[Herb]

Originally posted by andya
The only thing that seems odd is that the face (where the back of the belts touch) of the tensioner pulleys is curved slightly as are the idlers.



Andy

This is called crowning, and although I am not particularly familiar with the Ducati belt drive, I can state that crowned pulleys are normal in automotive belt drives. The theory is that the crown centres the belt on back drive pulleys and helps it track correctly. (This theory is taking a pounding at the moment in my industry and we are now using machined flat pulleys.)

[andya]

Hi Nelly
The pulley mounts are tight. Are the pulleys supposed to be curved?

[andya]

Can anyone confirm which way the engine runs, looking at the clutch

[Charlie]

Shove it in gear and turn the rear wheel all will be revealed.

[andya]

I would do that if the engine wasnt on my workbench!!!

[DC]

Originally posted by andya
I would do that if the engine wasnt on my workbench!!!

Um ok,

Take the plugs out, turn the clutch around with engine in gear and watch which way aroung the sprocket turns.

[nelly]

From the LHS (alternator) the crank turns anti clockwise.

[outtacontrolla]

CAM BELTS TURN ANTICLOCKWISE AS YOU LOOK AT ENGINE FROM R/H SIDE AND TENSIONERS MUST BE TURNED ANTICLOCKWISE TOO