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Timing Belt Tension

Posted: Thu Apr 25, 2013 2:33 am
by whitepaso
Does anyone know how to properly tension the timing belts when new ones are installed? My shop manual references a special tool be used until the reference mark is attained, or something like that, but not much else. Guess I was expecting some sort of force or "free play" value. And since I'm doing this at home, I don't have that special tool.

I looked high and low through the forum and can't find anything related to correct tension. As always, your wisdom is sincerely appreciated.

Re: Timing Belt Tension

Posted: Thu Apr 25, 2013 6:01 am
by 907pasonut
you have to go by gut feeling, it has to be tight, but not too tight...I think 15mm movement (side to side) on the belt half way between cam pulley and tensioner should be about right :beer:

Re: Timing Belt Tension

Posted: Thu Apr 25, 2013 6:06 am
by PasoRoo
Hi whitepaso,

If I'm correctly informed the play for the horizontal cylinder is 5mm and 6mm for the vertical one. This web site http://www.ducatisuite.com/belttension.htmlhas a description of the procedure using a 5mm or 6mm Allen key to measure the play between the belt and one of the rollers.

I can't claim to have used this method (yet), but I;ll have to soon to check the belts on mine.

Cheers,

Mike

Re: Timing Belt Tension

Posted: Thu Apr 25, 2013 7:59 am
by 907pasonut
thanks for the info Mike, I was checking mine in a different way (still have the covers off the belts) they are fairly close, just a little on the tight side :thumbup:

Re: Timing Belt Tension

Posted: Thu Apr 25, 2013 10:24 am
by higgy
+1 on the 5mm 6mm go no go method :beer: :beer: perfect tension everytime


You should be able to pass a 5mm allen between the belt and the idler pulley on either cylinder
A 6mm should not go through


use one hand :beer:

Re: Timing Belt Tension

Posted: Thu Apr 25, 2013 4:24 pm
by Derek
The 5mm Allen key method is good. The current method is to use a frequency measurement.
This from a recent Service Bulletin from Ducati North America.

>>> All previous and new model Ducati’s requiring belt tensioning now will be standardized to the below specifications.

IMPORTANT: When checking and adjusting timing belt tension at the recommended scheduled maintenance intervals, if tension reading is less than 70 Hz (minimum allowed value on all Ducati motorcycles), reset belt tension as follows:

Refer to the appropriate shop manuals for cam timing procedure and belt tension setup, then reset to the below tensions for service.

Model
Belt tension spec for new belts upon replacement Belt tension adjustment settings for used belts when inspected value is determined to be 70 Hz or less

All models:

Streetfighter, 1198, 1098, 1098R 999, 998, 996, 916, 848, 749, M1100, MS4, MS4R, MS4RS, ST4, SC, ST3, ST2, SS1000 HYM 1100, MTS 1100,MTS 1000, MS2R 1000, M696, MS2R 800, M620, M400, M695, SS800, MTS 620


New Belts: 110 Hz +/- 5, Horizontal and Vertical *

Used Belts: 90-100 Hz +/- 5, Horizontal and Vertical *

* Please note, these values may be inaccurate on previous Ducati Technical Data posters and service manuals. Data listed above should be considered the new standard and supersedes all previous bulletins and documentation.

Please print and post this bulletin to be displayed with the most current Ducati service poster.

Sincerely,
Ducati North America
Service Department <<<


Interestingly all models are now to be set a 110hz whereas previously the 2V models were set at 145Hz, quite a big change. Our bikes aren't mentioned but the 906 and 907 are mechanically identical to the ST2.

Re: Timing Belt Tension

Posted: Thu Apr 25, 2013 5:07 pm
by 20YearOwner
See page H28 of the Ducati Paso Service manual.

Note: Apply the dynamometric stretcher 88713.0748 and stretch it to the reference marks. Lock to a torque of 14.46 or 18.06 lb./ft. the mobile stretcher fixing.

There is a drawing of the stretcher on the page. It's not special you might find a similar in an auto parts store.

Best,
:)

Re: Timing Belt Tension

Posted: Thu Apr 25, 2013 8:37 pm
by plasmid
http://ducatitoolrental.com/2_Valve_Bel ... nt_RQ.html


Btw - why are they removing the oil pressure sensor?

Re: Timing Belt Tension

Posted: Fri Apr 26, 2013 6:34 am
by Andrew2

Re: Timing Belt Tension

Posted: Fri Apr 26, 2013 6:13 pm
by ir_joep
Hi
Can somebody tell me what the unit Hz is?

I only know it as a unit for frequency.

?????

thanks for putting me out of my misery.

kr joep

edit
IT is frequency. I did not thought this was possible
did learn somethig today :D

Re: Timing Belt Tension

Posted: Fri Apr 26, 2013 9:41 pm
by plasmid
ir_joep wrote:Hi
Can somebody tell me what the unit Hz is?

I only know it as a unit for frequency.

?????

thanks for putting me out of my misery.

kr joep

edit
IT is frequency. I did not thought this was possible
did learn somethig today :D


Hertz


In a way it's kind of nice to 'tune' your timing belts.

Reminds me of that symphony for 4 Ducati's, 2 Ferrari's and 1 Lambo that was never played.

Even better you can write a composition for certain tyres, on certain roads, and certain speeds.

Kinda like a score that extends over miles.

Re: Timing Belt Tension

Posted: Fri Apr 26, 2013 9:45 pm
by plasmid
plasmid wrote:http://ducatitoolrental.com/2_Valve_Bel ... nt_RQ.html


Btw - why are they removing the oil pressure sensor?

Looks like I deleted my other post.

5,6 is great or you can use a guitar/instrument tuner app and tune them to 110hz.

Just did mine yesterday. They looked nearly new, although they're 7-8 years old (few kms).

Re: Timing Belt Tension

Posted: Fri Apr 26, 2013 10:30 pm
by whitepaso
Great tips and links. Thank you all!

Re: Timing Belt Tension

Posted: Sat Apr 27, 2013 1:48 am
by lane1feathers
I used the 5/6mm A.K. rule when changing mine last year. I've done about 4000km since then and haven't skipped a tooth or snapped a belt. I've done some open throttle riding too trying to get the weber to run right (and keep up with the boys!) It's the easiest, cheapest way :thumbup:

Re: Timing Belt Tension

Posted: Sat Apr 27, 2013 6:01 am
by ir_joep
Hi,


Found this on a Dutch website. On the page below there is a english version about tuning cambelts with microphone and PC.

There is also a download link for a the needed program.

http://www.hqracing.nl/Techniek_pagina_ ... angen.html

Cheers Joep