748 Timing Belts

[Roy748Bip]

I've just serviced my new toy ('95 748) and replaced the timing belts. I didn't fancy paying the £370 quoted from my Dealer for the tensioner meter so I used Nelly's 4mm Allan Key method.

I just have one concern and that is on the horizontal cylinder when tensioned correctly the belt between the adjuster pulley and the opposite pulley is approximately 2mm apart. I don’t remember it being that close when I started. Is this OK? Or have I done something wrong?

Any help would be appreciated.

[simonducati]

I’m getting mine done for £135 tomorrow.

You tied it your self but when your engine go’s your going to have to pay a bit more then you were quoted
:lol::lol::lol::lol:

[skidlids]

Invest in a Snap-on or Facom tensioning tool, they are very similar to each other and a lot cheaper than the Ducati one.

[rockhopper]

Hmm, the only way that i can see something like that happening is if the belt was too long. There is no way you could over tension it so much without snaping the thing!

Also worth turning the engine over a few time and trying the tension again (by hand not on the button)

[PeteB]

Roy,

Is there a possibility that you turned the tensioning pulley the wrong way? ie you tensioned the belt by moving the pulley clockwise instead of A C/W ??

[nelly]

The allen key method, slipping it between the idler pulley is for 2V motors.
The 4V are a little more involved. You need to measure the belt deflection between the two cam pulleys. It should be 5mm.
Tenion the belts "tight", turn the motor over a couple of times and then line the timing marks up. Scibe or pencil a line on the cover behind the belt, between the pulleys. Use this as the datum to measure the 5mm deflection.
Tension the horizontal cylinder only.
The rotate the motor 3/4 turn anti clockwise to put the vertical cylinder at TDC. Then tension that belt.
Only add tension to the belts turning the tensioner anti clockwise.

[m1keyp]

Does anyone know the facom tensioner part number or description?

[Roy748Bip]

Nelly / PeteB

Thanks for the info, I seem to have done everything OK, except applied a 4mm deflection between the cam pulleys rather than 5mm.

Maybe i'm just worrying about nothing! I think i'll try to get a tension meter in the near future though.

[skidlids]

The info on the Facom tool part No. DM1.6

http://193.150.169.26/page/Ensemble_Fiche_Produit.asp?Lien_Id_Ensemble=2607


http://193.150.169.26/Frame.asp?langue=an&Cat=427

[Edited on 19-2-2005 by skidlids]

[moto748]

I understand ( and I await elaboration from those who know better than me) that not all 748 engines are the same, and they can take different belt part numbers. My bike although nominally a 748E, does not, in fact, have a an "E" engine, but a Bip engine, which has different belts.

Not saying this is Roy's problem, of course. Just thought it was worth mentioning.

[Shazaam!]

4V Belt tensioning tool $349

http://www.ca-cycleworks.com/shop/catalog/ducati/maint.html

[SPS]

Hi Guys,
This sounds real complicated.
I've just had mine done for Zero points!!
Got a good m8 who does de biz!!
Know what I mean!
I am a lucky old sod.
Cheers
SPS

[Mr_S]

Originally posted by moto748
I understand ( and I await elaboration from those who know better than me) that not all 748 engines are the same,

Correct, the later 748E engines had a "stepped" front cylinder head with the cam pulleys in a slightly different location.

This was so the same engine components could be used in the monster and allow clearance for the front wheel (common parts program after Texas Pacific takeover)

I discovered all this when I had a set of virtually new E heads intended to replace my existing Bip ones. They're not interchangeable, so were cannibalised for parts instead.....