Tdc

[revver]

Tdc

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Hi all just been reading the haynes manual to check valve clearances and it says to set the engine at TDC but it does not say how as far as i can see. The only bit is for the timing check but thats only for the horizontal cylinder. could anyone shed some light on the matter please, thanks.

[Scotty]

a long screwdriver down the spark plug hole ?

should be enough for valve clearance check no ?

[Stafford]

If the 600 has a sight glass on the left then when the two upper rockers are free and the line in the sight glass lines up with marker = TDC.

[BluprintZ]

Sparky plugs out, rocker covers off, stick it in fourth gear, preferably with the rear wheel off the deck.
Pick whichever cylinder you want to check first, stick your finger end where the plug used to be and slowly turn the rear wheel in a forward direction.
When you hear/feel pressure from the plug hole (escaping past your pinky), then stick something in the plug hole (i use a drinking straw or pencil), then support it as you again slowly rotate the rear wheel.
Once the straw/pencil/whatever, reaches the rocking point (just as the piston starts to go back down), that will be TDC and the rockers should have a bit of play in them.
You can now check the clearances.

G ; )

[revver]

Thank you all did think about screw driver but was worried about damaging barrels. But lots of good advive as per usual, Cheers.

[Capo]

Except for Stafford, ineffective crank angle has been ignored in the advice given.

[Stafford]

Except for Stafford, ineffective crank angle has been ignored in the advice given.

Well come on Capo explain more as we all need to learn, all I did was paraphrase the Ducati manual.

[Capo]

Ineffective crank angle is crank rotation in degrees with no movement of the piston. It occurs at both TDC & BDC
When the piston reaches TDC the crank continues, the rod angle changes and the piston commences the down direction.

At true tdc the rod is in alignment with both the big and small ends (true I believe for the so called desaxed arrangement also).

The most accurate way is to place a piston stop through the spark plug and using a degree wheel fixed to the crank rotate the engine forward until the piston contacts the stop, mark this on the degree wheel, then rotate the engine in the opposite direction until again the piston contacts the stop, mark the degree wheel. TDC is half way between the marks on the degree wheel.

[uksurfer]

Ineffective crank angle is crank rotation in degrees with no movement of the piston. It occurs at both TDC & BDC
When the piston reaches TDC the crank continues, the rod angle changes and the piston commences the down direction.

At true tdc the rod is in alignment with both the big and small ends (true I believe for the so called desaxed arrangement also).

The most accurate way is to place a piston stop through the spark plug and using a degree wheel fixed to the crank rotate the engine forward until the piston contacts the stop, mark this on the degree wheel, then rotate the engine in the opposite direction until again the piston contacts the stop, mark the degree wheel. TDC is half way between the marks on the degree wheel.

my thoughts exactly - good luck Revver

[Stafford]

Is that not a bit much for setting clearances on a M600? :eyepopping:

http://www.ducatisuite.com/valves.html

[Capo]

Probably yes, the intent is to have the follower on the base circle of the cam and there is a bit of tolerance here but assumes the cam is timed correctly.
I would recommend using the marks provided by Ducati.

Back in the day I set all timings in this manner and have even been known to stone cams to get timing perfect. When 1-2hp separates a good un from a bad un one tends to persue the Nth degree of f all.

[Dukedesmo]

If the 600 has a sight glass on the left then when the two upper rockers are free and the line in the sight glass lines up with marker = TDC.

No good if the belts are off though...

[Dookbob]

Just a quick one Capo, when you have checked the cam timing with your degree plate, (on any Duke you have owned) what was the greatest number of degrees that you may have found them to be out by. I,m just wondering if its a check worth doing.