Put the new belts on from cycleworks yesterday. Before I knacker anything. When horizontal cylinder is at TDC and the crank pulley dot is dead inline the two cam shaft pulleys look about half a tooth out?? Unless the cam pulleys are adjustable you would never get them lined up as the next tooth on the belt would be way out. When turning the engine over with the plugs out nothing catches. Like I say it just look slightly out to me.
I come across these sort of anomalies quite often and they have obvious been set that way since the factory. They nearly but don't quite line up but one tooth either way would be miles out. The pulleys are in fact adjustable and there is a screw blanking a hole in the cam cover at the opposite side. With the engine in the timing position a special tool is inserted to lock the cams while the belts are changed and tensioned with the pulleys screws loose. You could check the cam timing with a rod, something like a 5mm allen key, into the hole(s) to lock the camshafts.
So it’s normal? The crank pulley is spot on but the vertical and horizontal cam pulley are dead equally the same amount off the mark.
if you are not interested in adjusting the cam timing why not mark the old belts in relation to several teeth on the different cogs. belts off, mark the new belts same as the old and replace...
New belts are already on. It’s not that I’m not interested in doing the cam timing. Just don’t know how. As the bike was running spot on with tho old belts on and I’ve done nothing out of ordinary putting the new ones on but puzzled why the cam pulleys are both identically exactly the same off the mark.
Cams should be dialled in at a belt change ideally, makes a big difference to low speed throttle response, first time i did my hyp evo it was very noticeable how better mannered the bike was. Requires a timing disk, a plunger dti & a piston stop in spark plug hole to determine true TDC. Feeler gauge required to take rocker clesrance out of the equation. Google it for a better explanation than i can give. You may find the marks then come closer.
I’m more than up for doing it or getting it done in the very near future. For now I just want to know if due to the fact the cam wheels are half tooth out on the marks it is ok to run? Although when lining marks up before taking the old belts off I didn’t notice it being like this, it must of been? Any other way it would be a tooth or more out. The bike ran fine before. So for now until I get the cam timing dialled in will the bike be fine to use?
Yes. The timing will be exactly as it was before. The bike will just the same as before not which might not be quite optimal. Don't worry about it
Great. What’s a rough cost on getting the timing done and valve clearances. Not thinking about taking it to Ducati just a decent independent.
Getting the valve clearances checked and adjusted will probably be about 5-6 hours time but will depend on how many clearances need setting. Each will require new shims which an independent is unlikely to keep in stock although those who specialise in Ducatis possible will. So factor in the time at whatever your independent's rates are plus shims. To be clear about timing: "Dialling in the cams" is not something that is done at a normal service and not something that every mechanic has the ability to do well. The official procedure when changing the belts is to fit a special tool to lock the crankshaft at the timing position then fit to the special tools that mentioned earlier to each camshaft locking it in position. The new belts are fitted then, with the camshafts locked so that timing doesn't alter, the locking screws on the cam pulleys are loosened. This allow the belts to be tensioned without tension being applied by the closing springs. When the tension has been set the pulley screws are tightened again. Most owners and independents will just use the existing marks as you have done but the tensioning for each belt should be done with that cylinder at TDC with both valves closed so that the closing springs do not add any tension to the belts. Having said that, some owners and those looking to get the best performance from their bike will want to adjust the cam timing so that it is spot on to the designed spec. There is always some manufacturing tolerance so that on some bike the cam timing might be spot on but on others may be a few degrees out. This is where dialling in the cams comes in. By setting up a dial gauge on the valves and with a degree disc on the crank it is possible measure when each valve opens and closes relative to the engine position ie. before or after Top Dead Centre or Bottom Dead Centre. This tells the tuner by how much to adjust each camshaft to bring it to the specified figure. For 4V engines with separate inlet and exhaust cams this can be achieved fairly easily but for the 2V engine with both inlet and exhaust lobes on the same camshaft there is always going to be a compromise depending on how well the cam grind matches the spec. As you can imagine there is a fair bit of time involved in doing this so I wouldn't take guess at how much it would cost you. For a road bike I wouldn't bother unless you are obsessed with getting the last bit of performance out of it. You'd be better just making sure that the valve clearances are well with the specified parameters. Others may think otherwise. Dialling the cams should only need doing once. Once it is set, as long as the camshaft pulley screws are kept tight so the cams can't move, the timing will remain the same. I should also point out that it will make no difference whatsoever to the alignment of the cam pulley dots with the marks on the head. The position of the cam pulleys is determined by the length of belt between the bottom pulley and the camshaft pulley on the fixed tensioner side. This is a constant and will not vary by any perceptible amount. I hope that clarifies things for you.
That is a great explanation of the full procedure .... thanks ! Good point ! I've noticed that most of the better guides stress the importance of doing a few manual rotations of the engine , and then re-checking the belt tension .
Yes, I always do that myself. I fit the belts and pre-tension them so they are not loose, turn the engine over a couple of revolutions and check that everything still lines up as it should. Then I set the belt tensions and turn the engine over a few times before checking them again.
Derek. This is exactly what I did. It’s just the fact the cam pulleys was that little bit out I was a bit confused. great write up an explanation above. I will definitely get the valve clearances done in the near future though. As for cam timing. If the bike still goes as well as it did before I done the belts I’m fine with that.
the text also mentions an alignment difference of the pulley and marking of a few degrees http://www.desmodromico.com/officin...e/cambio-cinghie-motori-1000-1100-ds-evo.html
