TOP DEAD CENTRE,,,,,,my take

[Steptoe]

have been trying for some time how to find definite tdc on my motor,, after the "professionals" got it seriously wrong,, , cost me a head, ,,, they were close to 10 degrees out

eeinee way this is my take on pre-pulling a motor down,, just in case the pointer moves

http://www.youtube.com/watch?v=zZAOOKUxzuw

is now in my xs11 tool draw in my tool chest

[yamtom]

great video izatta RH ?

Hi,

Nice video, nice RH too. What is that bar thats this side of the number one pipe with the rubber covering the end. Is that half of something to simulate a centerstand?

[DGXSER]

Hey Steptoe,

I think I may have missed a bit of it or something. What is seems your finding is where the piston peaks in its travel. TDC is actually a few degrees of travel past that point. There is a certainamount of crank rotation where the piston is sitting still at the top of the stroke, maybe 5 degrees give or take. So finding the point where the piston tops out on travel is only part of finding TDC.

If you put a degree wheel on the timing plate, with a pointer mounted to any stationary part of the bike and pointing to a spot on your degree wheel. You can turn the crank to the point you hit the top of piston travel, and mark that spot where the pointer is at on the degree wheel. Then continue turning the crank until the piston begins moving down, at the point the piston JUST begins to move down, mark that point as well. Half way between those two marks is true TDC, and THAT is where the pointer should be on the T mark of the timing plate.

[tarzan]

I agree, that isn't top dead center.But it will get you close enough to set valve timing with the crank.That is what they are aiming for, right?

[dbeardslee]

Interesting video, but it seems like a lot of trouble to go through to find TDC. I just stick a dial gauge down into the spark plug hole and set the piston half way between where it stops moving up and where it starts moving down. I do this with the degree wheel already attached, and then bend my pointer a bit to point directly at TDC. Takes about 2 minutes. My $.02

[bikerphil]

I just stick a dial gauge down into the spark plug hole and set the piston half way between where it stops moving up and where it starts moving down.

+1, same here.

[Steptoe]

you guy's are right as usual,, wrong terminology

the bar on the engine protect bar is an unfinished cruising peg,,

[DGXSER]

Nothing to be sorry about. Alot of work went into that bit, and you made a nice vid of it all to. It is a good solid way to help find the top of piston travel. Which is important in finding TDC.

[fredintoon]

- - - I just stick a dial gauge down into the spark plug hole and set the piston half way between where it stops moving up and where it starts moving down. - - -

Hi dbeardslee,
lacking a dial gauge, I use a pencil and judge by feel. Thing is, in the top ~10º there's not much difference in feel or in measurement so yeah, you gotta guess at the middle of the "no difference" zone.