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Discussion Starter #21
I should have left it as is when it seemed to be running and idling well but the check engine light came on and since I couldn’t take it for a ride I decided to take the belts off and check things out, now the freaking thing almost wants to start but won’t , grrr. Something is slightly off but not sure what. Since I moved the crank during the shim job I really think it has something to do with that and the timing of the spark not synced
 

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At least you will have a good understanding of the thing when it will run. I think like you that it must be easier then I have read but maybe they are right.

Let us know your findings please.
 

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I just read the manual. It states that timing only works on one of the TDCs of the horizontal head and suggests that the special tool that locks the outer, front belt pulley to the right engine casing will only fit properly when the correct horizontal head TDC is chosen. Once the tool is locked on the right side of the engine, another special tool, same that is used to rotate the crank, is used to lock the crankshaft on the left side of the engine. So, if the special tools have not been used, it's possible that the timing was set-up using the wrong TDC.

The next step is to install the "head install tool" on the vertical head making sure that the variators are flush with the "head flat surface". This probably makes more sense when doing the job; there is a picture showing the variators end on from the right side with some reference lines. Fit and pre-tension the vertical belts and their pulleys then move to the front cylinder.

The head tool must then be placed on the front head, variators aligned again then add belts and pulleys and fully tension the front belt using the frequency tool.

The manual then states "remove the crankshaft locking tool" but surely the tool on the horizontal head has to be removed now too as it then states "rotate the motor 270 deg to get the vertical cylinder at TDC". Then fully tension the vertical belt using the frequency tool.

The shop manual is missing a lot of detail including whole parts in some sections.
 

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Read a little more. It seems, if I'm reading right, that the DVT motors don't have a crankshaft sensor like older motors but instead have individual timing sensors on the exhaust and inlet cams on both heads. This makes sense; as long as the procedure above is followed, both heads' valve timing are in synch with each other. The adjustment of timing due to the DVT variators is tracked exactly with the individual cam timing sensors. Pretty cool, pretty complex.

On a side-note, on the right side cover, there is a small plug. The manual calls it "plug". It is located over the right side end of crank shaft. On earlier motors, this is where the crankshaft position sensor was located.
 

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Discussion Starter #26
That’s awesome info, thanks. The first post I had read but the second post I didn’t see in the manual. Maybe the sensor I thought is cps is in fact not, the manual calls it “sensor” lol. It’s on the left side just behind the water pump, it has a screw in plug on the side when removed you can see the space from teeth to sensor. There are the same sensors on each cam so maybe they all work together. The thing I’m trying to understand is- if the belts are off and I turn the crank how do I know when tdc of compression stroke is, since all the cams are at rest position every stroke will basically be compression stroke. I don’t see how that crank special holding tool knows which stroke is which because when the dot on crank pulley line up with the mark on the case it’s the same every rotation
 

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My guess is that the special tool that locks the outer pulley to the right side casing will only do so when the horizontal cylinder is at the correct TDC to do the belt timing; the manual does not state if its at the top of compression or the top of exhaust. The older motors were all about alignment of dots/marks but it seems that the DVT needs a few special tools to do this job right.

I appreciate you sharing your story; my bike only has just over 1k km on it and a couple years of warranty left.
 

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There are 2 positions of the horizontal piston that would appear to be TDC on the compression stroke. It’s impossible to tell which one is correct without the crank position holding tool which bolts onto the engine cases meshing with the lower belt pulley. That tool will only fit when the horizontal piston is on the correct TDC.

Warren
 

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Hi neulee: Did you mean to say there's a TDC at the top of the compression stroke and another at the top of the exhaust stroke? I don't understand two TDCs on the same stroke.

If you have done this job can you explain something to me? The procedure starts locking the cam belt drive pulley with the horizontal cylinder at TDC (one of them, i
m guessing the compression stroke) but the next step is to work on the vertical head. Its compression TDC are surely at 270 deg after the horizontal head as confirmed. I'm missing something.
 

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There are 2 positions of the horizontal piston that would appear to be TDC on the compression stroke. It’s impossible to tell which one is correct without the crank position holding tool which bolts onto the engine cases meshing with the lower belt pulley. That tool will only fit when the horizontal piston is on the correct TDC
I still don't wrap my head around this. How the engine "knows" it's on the "wrong" cycle. After all it's the relative position of the cams that decide if the inlet open to suck air or if the valves are closed for detonation (at, and after TDC).
 

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Ricko: As I understand it, there is only one condition that allows the special tool to interlock with the teeth of the outer belt drive pulley and fasten to the motor casing and when these stars align, the front head is at the correct TDC (still assuming this to be at the top of the compression stroke).
 

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Discussion Starter #33
Yes this is where I get confused. I think it has to do with when the spark plug gets the signal to fire on the horizontal cylinder which will set the tdc , also if this special tool only hooks up in one position then the tdc of the compression and tdc of exhaust will be different and the dot on pulley and mark on case will not line up in both cases
 

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Let's say I'm Luigi at the factory. How the hell can I assemble this engine if it needs to be hooked to a diag system? I can't have to plug in every sensor just to know where to put the straps?

The bottom end is just doing the same pumping action every revolution. Add a crank sensor and you have a pulse every rotation. How a pulse of the cps can be different after the compressing stroke or before the admission of fuel? To differentiate the "good" TDC of the "wrong" one?

I'm also puzzled about half people saying it's rocket science and the other half saying it's almost as usual.
 

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Discussion Starter #35
Maybe Luigi is the magician who has the magical powers. Anyway taking a break from the bike this weekend and going snowmobiling while the snow is still here. I’ll still be looking for answers to this mystery though.
 

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Discussion Starter #36
I used translator for this site Team desmodromico - Cambio cinghie motori DVT not the best translating but good enough. From what I understand when you lock the cams in place the marks on the variators don’t line up with the head, the gear or outer tooth part of the pulley still moves (DVT action) so this needs to be done to align the marks when installing the belt. I will have to remove valve covers etc to check this all out but that will only be in a few days. There is also a drawing for the tdc control tool so I think with the measurements I’ll be able to line up the main pulley with the proper tdc, which I still don’t under stand how it know what rotation it’s on when the pulleys teeth are all the same
 

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I think I cached why the tool only fit on one every two rotations of the crank.

Since the drive pulley have 20 theeths and the cam pulley have 27, the tool will align correctly on one revolution and on the next revolution would need to fit over the theeths.

Still not found a reason why it matters on which TDC you line up the cams.
 

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it's a bit brutal listening to the guy, but hopefully will take some of the mystery out of it. What's important to remember is that lower pulley is not the crankshaft, it's a secondary pulley driven by a gear inside the crankcase to the crankshaft. This is done because it's just not feasible to bring the belts all the way down to the crankshaft. It has 20 teeth simply because it's a good size for a toothed belt and fits in the space. required. The issue seems to be that the crank doesn't have a visible TDC mark or an opening in the case that you could see. For some design reason Ducati just couldn't get a port to the crankshaft, so they put this mark up where you can see it on the lower belt pulley. This pulley is not geared 1 to 1 with the crank for design and space reasons and this is why that dot will only come to the index mark at TDC for a number of revolutions.
The absolute key to it all is to be sure nothing moves while the belts are off.
 

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Discussion Starter #40
That’s my problem. I moved the crank doing the shims so the valves wouldnt fall in and I didnt take note of how many rotations I did
 
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