Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > timing belts

[custard]

Being slightly paranoid about timing belts, does anybody have any advice on how I go about checking tension of belts on my 748bp 99. I had a belt snap on a BMW (car) once, I've never been the same since. Another question I worry about the nut or bolt on the alternator, I've heard stories of this coming loose and causing all sorts of probs. Any advice anybody???

[nelly]

There were numerous threads on these on the old board, but the basics are;
Belt tension. If you haven't got a tension meter, and I'm guessing you haven't, the tension is correct when you have got about 3 or 4mm belt deflection on the run between the cam pulleys using "moderate" finger pressure.
Another "trick" is the twist method. You should be just about able to twist the belt 45 degrees, although IMO this is less accurate.
The alternator nut was a gremlin that affected pre '99 bikes mostly. The quality of the nut wasn't very good and it unscrewed itself. This let the flywheel come adrift and could cause all sorts of damage, from minor scuffing to wiping out the crank.
There is a new design of nut now that is supposed to prevent this happening??
It doesn't, but is no where near as common.
Buy a Haynes, and check how to check/do the jobs. They're not too hard with a bit of common sense

[custard]

Thanks, I'll have a go. Forgive me if my questions are a little bit old hat, but Ducati's and biking are quite new to me. My 748 is my first ever bike (had it 8 months now) and loving every second of it. Thanks again for the advice

[kfz2]

To add to nelys post..

Its quite amazing how loose the belts appera to be on a cold engine compared to a car engine.

The motor grows so much you see so its important the belts arecorrectly tensioned .

When i do belts i like to warm the bike up then check the tension again, if there like a bow string thne need to be slacker. As Nelly says about 3-4mm on a four valver, about 5mm on a 2 valver.

You will soon hear a awfull racket from the rotor if the boltsnut comes off so if you do its time to check. THe washer usually ends up comming out with the oil, so allways chekc your oil for bits.

Kev

[custard]

I have just done an oil change, is it common for there to be some small bits around the filter bolt (the one with the guaze filter on it that goes in the side)

[scoot]

depending on how new the motor is you will get a little bit of metal fillings