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Discussion Starter · #1 ·
hi bit of help please.i bought a 999 bottom end engine.i replaced the cylinders pistons and heads and all pulleys .so when i got to putting the belts on thats where it gets odd .i set the layshaft pulley mark to the mark on the clutch cover so the vertical cylinder is at TDC and it isnt .so do i just forget about the layshaft pulley mark and just go by the TDC .thanks for any help guys.
 

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Ricko is righto! Unlike the bevel drives, the belt drives are at TDC on the horiz. cyl. when the dots line up. Be aware the vert. cyl. cams will be loaded[valves open] when the dots are aligned.
You will have to hold them when installing the belt.
 

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Ricko is righto! Unlike the bevel drives, the belt drives are at TDC on the horiz. cyl. when the dots line up. Be aware the vert. cyl. cams will be loaded[valves open] when the dots are aligned.
You will have to hold them when installing the belt.
I rotate cams and driveshaft 5 teeth or so in the same direction (counterclockwise) so the valves are closed and springs unloaded on the Vertical cylinder, install the belt, then rotate back to make sure all marks line up. Much easier than trying to work against the closer springs.
 

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Discussion Starter · #7 ·
thanks guys great information for the cams but i tried the horizontal and that was not at TDC either so what do you recon guys.thanks again in advance ........
 

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Pictures would help
But if you are saying that when the timing mark on the layshaft pulley lines up with the slice mark on the clutch housing you are NOT at TDC on the horizontal something clearly is not right. Look at the timing gears under the left side cover to make sure the timing dots are lined up properly on the crankshaft to layshaft.

Be sure also that the layshaft pulley is marked correctly, is the correct pulley. You should be able to match both layshaft pulleys and they should not be the same as the camshaft pulleys (non-adjustable).
 

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Morning ducvet. I have witnessed the very same problem with a 999rs. After every timing mark on crank, gears and cam were checked the thing wouldn’t time at tdc on the horizontal. It ran after manually re-timing. It runs with the timing marks all over the place. Bizarre.
 

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‘05 749R, ‘89 851/926, 749R/999RS project
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Morning ducvet. I have witnessed the very same problem with a 999rs. After every timing mark on crank, gears and cam were checked the thing wouldn’t time at tdc on the horizontal. It ran after manually re-timing. It runs with the timing marks all over the place. Bizarre.
Hmmm, I wonder who's (heap of shit) bike that would be, gotta feel sorry for that poor bugger, lol. Thanks again for casting an experienced eye over it, I thought I was going nuckin' futs there for a while.

Here's where my layshaft pully sat with the horizintal cylinder at TDC:


I did exactly as the last post say's, fearing I'd somehow cocked up the timing dots on the other side when I replaced the RS timing gear with a 749R unit (to suit my non-RS ignition/pick-up), but all checked out ok. In the end I just went back to first principles: the timing mark is only a convenient indicator, the important thing is the piston being at TDC on compression, not where the marks sit in relation to each other. My engine was a fresh rebuild, chock-a block full of new crank/pistons/cylinders from a very well known international Ducati specialist, not a home build, so not sure how it came about but it sure caused some head scratching.
 

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Discussion Starter · #12 ·
hi guys i took the stater cover of and removed the flywheel out and there it was the dots where a country mile out 12 teeth so got the dots in the correct place and every thing is working ok when the mark on the lay shaft pulley is in line with the line on the clutch cover the horizontal cylinder piston is at TDC so sorted guys. thanks for your advice guys.
 

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Good to see progress!
Once being a hired duc tech I was to do a belt swap and I checked the belt marks and all matched up prior fine, however when putting it back there were TWO marks on each side of the driving pulley :O
5050 chance, you can take a guess if the pulley or me won :) Always check further than just one mark is my tip.
 
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