ST4S 996 engine Humour me for a bit but soon I'll be doing the valve job. Lets assume I cock it up somehow and the timing is entirely lost from a ton of dicking about, removing the camshafts etc etc. If I have understood everything correctly. Would I just need to get the flywheel mark to the correct spot, gentle not to damage any valves out for any reason. Then get all the pulleys lined up to their timing marks and the engine should be "in time" again? Further more last time I did the belts, I removed the spark plugs, but it was an absolute nightmare to turn the top right pulley by hand, is that normal? In videos people seem to turn it completely freely but I never managed to do that. Cheers Martin
Long story short ..... Yes ! With both pistons at TDC there will always be one camshaft ( pulley ) that is under spring pressure , and it will need a bit of force to turn ( and hold it ) at the correct position . BTW - Nothing to do with " valve springs " ..... ...... because there aren't any ! ......
ah fantastic. its removes a massive stress imo knowing that I can always get back to what its meant to be if I really cock it up. tbf I don't envision needing to make any real changes given it runs smooth as, but worth checking the rocker arms./cams
This tool makes turning the engine so much easier than manhandling the rear wheel, etc... Worth every penny, even if you only use it once imo! https://gbmotorcycleproducts.com/ducati-crank-tool/
There are 5 pulleys in all , that need to be on their timing marks - two cam pulleys for each cylinder , and the bottom one that both belts run on . If they all line up on their spots , you are golden !
Please note ....don't try to turn the motor over with this tool ... until both plugs removed.......the tabs on the tool will break off .....(allegedly) ...
beauty, thanks i remember my MT09 was similar(i know much easier valve train).you lined up the timing mark on the flywheel, lined up the camshafts and that was that. it'll keep an eye on that thanks
That cam is under spring pressure (despite being Desmo, there are still valve springs) whilst in that position and is tricky to hold in place. You can get a cam holding tool that sits between the cams and stops it turning for not much money (google Ducati 996 cam holding tool) though with my 916, I can't use one as, having 'degreed' the cams it doesn't quite line up so I end up just holding it (a camshaft nut tool helps to hold it here). Otherwise, as above line up all the dots, make sure you adjust the tensioner pulley in the correct direction (or the belt may rub against itself at the pinch-point) and you're good to go but do turn the engine over a couple of times by hand with no plugs in just to be sure all is good.
yeah when i first did it years ago(i was shitting myself ). i ended up just muscling it back into place. it hurt a lot. this time i bought the holding tool haha I guess the videos where misleading.
