Timing Belt Install Question.

kirk332 · Post by **kirk332** » Fri Nov 02, 2007 11:42 am

Reading older posts on this subject makes it sound so'oo easy, a 45 min job, ha! I seem to be having some difficulty.

The belt doesn't just slip over both gears. It's very tight! Do you need to rotate the engine while stretching the belt on? I had a fair bit of trouble removing the belts, so much so in-fact, that they got damaged when being removed. Just to state the obvious, both idler and tension bearings have been removed.
Cheers

Desmo_Demon · Post by **Desmo_Demon** » Fri Nov 02, 2007 1:02 pm

It does seem to be a tight fit.....what I end up doing is just barely getting the belt over the edge of each cam pulley, then slowly start working it over into their proper location. You cannot put it over one pulley and then try to get it over the other. Also, definitely make sure that the teeth are in the grooves on the lower pulley. I've had the belt slip over so it was teeth on top of teeth, and this takes away a lot of the freeplay.

I would never recommend turning the motor without the belts in their proper location, but I fgure it could work as long as the cams turn with the engine and you don't skip a tooth and screw up the cam timing (which can result in bent valves). I've never had to rotate the engine to change belts, and I've changed the belts on the Pantah 750, DesmoDue, DesmoQuattro, and Testastretta engines.

kirk332 · Post by **kirk332** » Sat Nov 03, 2007 1:49 am

Thanks for the reply. I am trying, to no avail, to insert a picture of my timing gears. They have a washer on them which is the same size as the gear, which prevents the belt from smoothly pushing into place. Arr

How do I insert a picture to show you what I mean?
Cheers

h1a · Post by **h1a** » Sat Nov 03, 2007 1:48 pm

First, you'll need a host to link to the pictures. http://www.photobucket.com has free picture hosting. Sign up for a free account and then follow the rest of the instructions.

The pictures you send must be on your computer.

Log into your photobucket.com account.

Where it says " Add Pictures " , click on multiple pictures ( click on how ever many you'll be adding ) and then click " browse".

You'll need to go where you saved your pictures, usually " MY PICTURES "

( I use Kodak software, so I click on "Kodak Pictures" inside of "my pictures")

Click on the picture ( single pic ) that you want to add.

Repeat as many times as necessary.

Hit " submit ".

It will let you know when the pictures are successfully downloaded.

Then go under the picture and "copy" the [img]picture%20description%20in%20here[/img] address.

That is what you copy into the thread post.

jomo · Post by **jomo** » Sun Nov 04, 2007 9:14 am

When I change the belts, I borrow the correct tool to remove the pulley net from my local bike mechanic. You also have to make sure the woodruff key that locates the pulley doesn't slip out of position when fitting the pulley. Make sure you do it with plenty of light. I normally get the mechanic to replace the belts and check the valve clearances at the same time.

When I fisrt got my Paso about 11 years ago I changed the belts without the special tool and vowed never to do it again. I still don't know how I did it, but I know there was a lot of bad things I said about Ducati engineers that day

ducapaso · Post by **ducapaso** » Sun Nov 04, 2007 11:06 am

I've changed a lot of timing belts in my like as a car mechanic (one or two lives ago :laugh: ) You need strong nails in your fingers to pull off belts from their seat! Otherwise, belts could never be able to stay there while an engine is running at 9500 rpms!
To make the work easier, you can take the fixed bearing away and loose the tension bearing at all.
Another tip: If the fixed bearing is the "old solution" (a pair of std bearings), it might be the right time to switc to a "recent solution",
the special bearing installed on the newer desmodue starting from earlier pasos

Tamburinifan · Post by **Tamburinifan** » Sun Nov 04, 2007 12:05 pm

They have a washer on them which is the same size as the gear, which prevents the belt from smoothly pushing into place.

Is the washer really needed?!?

Took of mine belts w the same problems, what a PITA....
Looked at my M900 -97, no washer there and works w/o problems.
Maybe Ducati later realized the washer wasn`t needed and skipped them? Or have I missed something?

kirk332 · Post by **kirk332** » Mon Nov 05, 2007 4:30 am

After several hours of cursing and making numerous phone calls to the Ducati bike shop where I purchased said belts, it was established that they had supplied the wrong P/N belts. I have just proven the old adage, "you can't fit a square peg in a round hole". The original belts I removed had half round teeth where as the new belts have square teeth. Second lot of new belts arrive tomorrow, hopefully!

Is the washer really needed?!?

One of the phone calls made, for the above, established that the washer is easily removed and that they are not required. Apparently they were only used on a few models then removed altogether.
Cheers

kirk332 · Post by **kirk332** » Mon Nov 05, 2007 5:35 am

Sorry guys just checking out my new found photo input skills, thanks to h1a.
Cheers

Tamburinifan · Post by **Tamburinifan** » Mon Nov 05, 2007 10:28 am

One of the phone calls made, for the above, established that the washer is easily removed and that they are not required. Apparently they were only used on a few models then removed altogether.

Great!
Sometimes even my two braincells work...

Desmo_Demon · Post by **Desmo_Demon** » Mon Nov 05, 2007 4:29 pm

kirk332 wrote:The original belts I removed had half round teeth where as the new belts have square teeth.

The belt that I removed from my Paso had the round teeth, but the newer belt (same as the Monster 750 and SuperSport 750) had the square teeth, so don't be too surprised if the new belts have square teeth.

kirk332 wrote:...established that the washer is easily removed and that they are not required. Apparently they were only used on a few models then removed altogether.

I have heard of some people removing the washer that forms that lip with regular pliers or Channel-lock pliers, but I cannot confirm this, plus yours look like they are held into place by the cam nut. My Paso didn't have those washers on them, so it was fairly easy to slip them over the pullies.

Post by **paso750** » Mon Nov 05, 2007 5:43 pm

kirk332 wrote:
The original belts I removed had half round teeth where as the new belts have square teeth.

The belt that I removed from my Paso had the round teeth, but the newer belt (same as the Monster 750 and SuperSport 750) had the square teeth, so don't be too surprised if the new belts have square teeth.

note though that for round and square teeth belts there are different pulleys used ! Using square teeth belts on round teeth pulleys may be risky as the belt may slip or jump by a tooth.

Desmo_Demon · Post by **Desmo_Demon** » Mon Nov 05, 2007 6:09 pm

paso750 wrote:note though that for round and square teeth belts there are different pulleys used ! Using square teeth belts on round teeth pulleys may be risky as the belt may slip or jump by a tooth.

Hmmmm...didn't think of that, and you are correct. I may have to change my belts, again. :ugh:

Post by **paso750** » Mon Nov 05, 2007 6:13 pm

I have to admit I never thought of this myself. The issue only popped up when I changed to adjustible belt pulleys. With them I needed to use different belts and also change the lower pulley.

G.

Finnpaso · Post by **Finnpaso** » Mon Nov 05, 2007 6:53 pm

I have removed spacers long time ago and no anykind of problem. Only much easier to change belts...