S4R belt change?

[blue_toaster]

I have an S4R I bought in the summer and it was pointed out that the belts were changed just a few hundred miles before I bought it. Looking through the papers today I noticed that a few hundred miles before I bought it was in 2008 :eyepopping:

I know the schedule says check the belts at 6000 miles, and change at 12000, but should they be changed on a time basis as well?

I bought the bike with 4,500ish miles on it, the belts had been changed 3 years earlier at 4,200 miles. I've done a couple of thousand miles since.

Any thoughts?

[Robot]

Service schedule is every 2 years (regardless of mileage)!
Better safe than sorry?

[He11cat]

That old chesnut !!
Yes had that with both my monsters.
Only x amount of miles done on the belts....
Never take it as gospel usually put in as a selling point.

First monster had only done 26 miles in a year .. Because it had sat there after MOT until the next one .. First thing it had done belt change!

2nd monster only done so many miles since it's belts where done..
Bike had been lavished as was wifes bike ( hmm did you like your wife?)
the belts only had a little amount of mileage popped on them!
But that was 4 years ago .

Always change the belts be it mileage or over 2 years it's just not worth the risk .



It is always best to read through every scrap of paper that comes with the bike.
You can find out so much...

Mine was crash damaged and had a bent frame so much for lavised in care .
There are honest sellers and so very dishonest ones. Sadly always be scepical at the end of the day the person wants shot of the bike and wants the cash sadly in many cases nit always the truth is bent or totally distorted to get that sale.

[blue_toaster]

oh well, I guess I'd better put new belts on the list. Is it something I can sensibly do at home?

[gary tompkins]

Depends on how competent a DIY mechanic you are and what tools you have available. I can usually swap belts in less than an hour on my aircooled 900, but I've had a fair bit of practice. No idea how much more work's involved in belt replacement on your bike. I've never owned a 4V watercooled monster. The desmo shims might need checking or adjustment too, and as the belts have to come off for this it could be worth getting the engine service/belts done at a dealers.

[blue_toaster]

I'm competent enough to have changed heads and timing belts on cars, though that was on cars worth less than a garage would charge to do the work so there was little to lose. I'll look through the manual and will get prices from some local garages and see what comes out.

[Capo]

If you don't know already, be prepared for a shock when they tell you the price of the Ducati belts.

[blue_toaster]

They don't look too bad here

http://www.bainesracing.co.uk/ducati-shop.html

[gary tompkins]

I think the S4R uses a different (read more expensive) spec belt that the earlier S4

Make sure you price the right ones and/or match Ducati part numbers

[Scott1]

There's some pretty good vids on YouTube that go through 4v belt changes, might not have the exact bike but they might be a good indicator about tools etc.

[Nickj]

I'm competent enough to have changed heads and timing belts on cars.

Pretty similar then, essentially its a twin cam head. I imagine that there will be timing marks on all of the pullies and maybe holes for locking pins on the cam drive wheels (got them on my 2V but never needed to use them)

[chris yeatman]

If you don't know already, be prepared for a shock when they tell you the price of the Ducati belts.

tell me about it, just brought some more new belts as its come up for two years since done mine last. :eek:

[jerry]

S4 and S4r belts are not cheap but easy to change at home in a couple of hours

[Flip]

Do you need to use a cam locking tool for the twin cam head models?

There's loads on eBay for a few squiddlys but are they really needed?

I have never used one on my 2 valve Monster (same as NickJ) but have been asked to change the belts on a 748 so just wondered while people are asking.

Cheers!

[chris yeatman]

last time i done mine i used one, makes life easier with it.

[Dukedesmo]

Do you need to use a cam locking tool for the twin cam head models?



You don't need one but when the timing marks lineup (horiz cyl @ TDC) the vertical cylinder intake cam will be constantly trying to go backwards to get off the cam, so you might find it easier to use the tool.

Otherwise it's a straightforward job.

N.B. Check for timing marks on the pullies though - the Desmoquattro engines (916 & 996) should have them but Testastretta engines (998) don't. It's easy enough to mark before removing the belts but a bit of a ****ter once you've got the belts off and realised there are no marks.

You can check valve clearances with the belts and cams in place but you should check the rockers (openers in particular) for flaking chrome and you need to pull the cams out to do this and to swap any shims.

BTW belts for a 916/996 cost around £50 each from Ducati...

[blue_toaster]

so basically check for timing marks, mark them if there aren't any, lock the cams if I have a tool, change belts and robert's your relative.

Anything else to check? e.g. do the tensioners need removing? or are they sprung?

I'm assuming 2 cam locking tools are recommended, one for each head?

[chris yeatman]

I'm assuming 2 cam locking tools are recommended, one for each head?

no just the vertical head, inlet cam.

[Dukedesmo]

so basically check for timing marks, mark them if there aren't any, lock the cams if I have a tool, change belts and robert's your relative.

Anything else to check? e.g. do the tensioners need removing? or are they sprung?

I'm assuming 2 cam locking tools are recommended, one for each head?

As said above only one lock tool required as the horizontal cyl cams don't move (unless you turn them) but you can also do without if you're persitant.

The tensioners are just bolted down, no spring so you need to manually tension the belt - belt tension and how to set it is another thread in itself.

Make sure you adjust the tensioner the correct way otherwise the teeth on the belt get so close to those running over the non-adjustable pulley that they will shred the teeth with dire consequences.

You may need to remove the adjustable pulley to get the new belts on and it's worth checking the bearings in both the adjustable and fixed pullies as they can fail and they're cheap enough to replace (if you get them from a bearing supplier).

Basically it's not a difficult job but it needs to be done right as a belt failure is a very expensive repair.

There's a good 'how to' for a 916 here, other than bodywork etc it should be the same procedure (different belt part no though); http://www.tassell.co.uk/belt_change.htm

IMO it is very important to check the rockers for chrome flaking on a regular basis and whilst you're doing the belts it's not much more time to do it, you may well be lucky but a flaked rocker can ruin your cams.

Good luck. :thumbsup:

[jerry]

Head locking tool not required just use some forked long nose pliers to hold back inlet cam against its spring easy peasy

[Martin C]

I've run a 916-engined ST4 for about 3 years & 25,000 miles between belt changes, but I believe very low mileage does require changing them on a time basis. Changing the belts on a water-cooled 4-valver like the 916 isn't much harder than on an air-cooled 2-valver, but yes - STUDY THE AVAILABLE INFO!!

Provided you're reasonably patient & handy, no special tools are needed, apart from a torque wrench - which any sensible Ducati DIY-er should have anyway.

[blue_toaster]

I've booked the bike into Ducati Coventry next week for the belts to be changed and the rockers to be inspected for flaking. I wasn't aware of the flaking concern before Dukedesmo raised it and would prefer to know the bike is right. For belts alone I'd do it myself, talking to the garage though they go as far as taking the cams out to inspect the rockers and while I'll do that on a cheap bike, my S4R is worth too much to risk it.

[gary tompkins]

I thought the flaking rocker issue was limited to early 916 engines in superbikes and original S4 monster? I know Scotty had this problem on his S4 challenge bike, so it's not unheard of.. and very expensive to fix, but would have expected the much later S4R engines to be sound from this point of view.

[Dukedesmo]

All Desmoquattro engines can suffer from flaking rockers, although some models/years seem worse than others. I have replaced 9 opener rockers on my 916.

It's a problem that Ducati never solved (except by stopping production of the engines) and one that they (at least Ducati UK) behaved quite badly over.

In the USA they replaced many FOC but as usual here in the UK we pay more and get less...

[gary tompkins]

I appreciate you had to swap rockers on your 916 motor.. an engine well known for having this problem

But has anyone actually documented or seen evidence of this issue on the latter 996, 998 or Testaretta used in models like the S4R and S4Rs?

Bearing in mind Blue Toaster (original poster) was specifically asking about belt changes on an S4R... not the 916

[Dukedesmo]

All Desmoquattro use the same rocker arms. I believe the S4R uses a 996 Desmoquattro engine? if so then the same problem can occur.

Testastretta engines have a totally different rocker setup and don't have the same problems. AFAIK S4RS uses a Testastretta (998/999) engine.

[Capo]

John Hackett was instrumental in curing the flaking rocker problem, he came up with a new hard overlay process that was subseqently adopted by the factory. Cases of overlay degradation from that point onward are rare and are down to a manufacturing defect in that item alone rather than a flawed process as was the case before.

[blue_toaster]

I did search the net and found rare mentions of S4R issues, it seems the 916 engine was worst. Capo, do you know when the manufacturing process change was introduced?

[Unit 18]

Some 996 SP's had the rocker problem.

[jerry]

The worst bike for Rocker flaking is the 748 as it revved harder also the only one that regularly bashed closers to death too, but all DesmoQauttro's can get it , my S4 has had 5 openers replaced ,,
but if you buy the replacements in USA they are much cheaper last lot cost me £30 in USA and they had been treated by megacyle superhardening............UK price £108!!!!!!!!!!

[Unit 18]

Newman Cams are very good, I think it was a 996SP (not 100% sure) that had worn the rockers and one of the cam lobes, which had been discontinued. They rebuilt the cam and saved the day.
http://www.newman-cams.com/

[gary tompkins]

Is this rocker wear simply caused by poor quality manufacturing or are other factors to blame, such as oil starvation to the valve gear, or oil thinning due to overheating? I note that later engines had additional low level oil coolers installed, and wonder if this reliability issue prompted the upgrade.

[Dukedesmo]

The cause is poor quality plating. Apparently early desmoquattro engines (851, 888 and first year 916) rarely suffer but then the plating of the rockers was outsourced to a different supplier which is when the major problems began.

Wear is increased if valve clearances are not set correctly - too tight and the chrome wears away, too loose and it is bashed off.

One popular theory as to why the 748 seems more prone is that they are often bought as a 'budget' ducati by someone who then skimps on maintenance to meet their budget, so valve clearances are left out of spec, which combined with a higher revving engine causes more wear. If left unchecked the worn rocker will damage the cam.

Personally I don't believe oil starvation or temperature makes a significant difference but it is generally recommended to use a good quality thick (15/50 or 20/50) oil.

For a desmoquattro owner; happiness is not finding any 'glitter' in the oil when you change it ... ;)

[jerry]

It is important not to rev the engine more than 1500rpm until at least 90 seconds after starting to let oil circulate to the heads ,,, oil starvation is a possibility at staty up if the bike is cold or been left to stand a long time , always use an oil in 15-50w range in desmoquattros not 10-40 they really need it .

[roundrock]

No one seems to mention another crucial point when changing the belts is the tension.
Too loose and the re is a possibility of slipping and to tight and snapping??

[Capo]

No one seems to mention another crucial point when changing the belts is the tension.
Too loose and the re is a possibility of slipping and to tight and snapping??

I think that it goes without saying, its part of the process

[roundrock]

What tool is used to obtain the correct belt tension when tightening the tensioner wheel?

[Dukedesmo]

What tool is used to obtain the correct belt tension when tightening the tensioner wheel?

There are many ways of tensioning, I use a 'Facom' gauge, like this; http://www.uktools.com/timing-belt-tension-gauge-p-12389.html

[gary tompkins]

I use a heavy duty fishing spring balance on mine

Others use the allen key feeler gauge method between belt and roller

[Dukedesmo]

Others use the allen key feeler gauge method between belt and roller

Which is OK on a 2v with roller tensioners but a 4v (S4R etc) have tensioner pullies with 'sides' on them so you can't do this.

[gary tompkins]

There are many ways of tensioning, I use a 'Facom' gauge, like this; http://www.uktools.com/timing-belt-tension-gauge-p-12389.html

I've been trying to suss out how this setting tool works. Does it just check the belt deflection between the forks of the clamp plate? If so it'll only really measure the belt tension over a very small area - looks like about 5 teeth. Would that be enough the set tension accurately? Maybe I'm miss-reading the way it's used on the 4V motor?

[Dukedesmo]

I've been trying to suss out how this setting tool works. Does it just check the belt deflection between the forks of the clamp plate?

Effectively yes, but I have double-checked it against various other methods, including the official Ducati tool of the day and it is consistent (enough). The only place it'll fit on a 4v is between the cam pullies.

That said I don't believe that tension is as critical as many say. Set your belt tension and then check it again in a few hundred/thousand miles to see what I mean.

Whilst this this new-fangled sonic belt tensioning is no doubt accurate, I think you could get too hung up over a mhz or two.

[blue_toaster]

woohoo, belts changed and rockers inspected, all good and none need changing. The dealer took photos of them while the bike was in bits for me to see.