I know you need to be at TDC when installing the cam, but you can have TDC at the compression stroke AND the exhaust stroke. With the valve cover off, how can you tell which TDC you are at? Does it matter, or do you just have to make sure that the "I" mark is lined up in the peep hole?
Thanks

 

Believe should be on compression. All valves down.

 

you need a service manual to be sure unless someone has it ther in front of them.

Let me go check my wolvy manual..............

Should be a T that you line up with a stationary pointer for top dead center on the compression stroke. And the cam should have a l that will be lined up with a pointer on the head.

 

what bike are you talking about?...yfz450...you line the 2 marks up, and you know if it's the right stroke by looking at the cam's themselves, the left one should have a mark going 9:00 and 12:00 position, and the right cam should have a 12:00 and a 3:00...hope this helps.

 

<div class="FTQUOTE"><begin quote>I know you need to be at TDC when installing the cam, but you can have TDC at the compression stroke AND the exhaust stroke. </end quote></div>
Like imsam77 said, the engnie does not know what stroke it is on with the cam out. The only thing that tells which stroke it is on is the cam(s).
In other words, if the piston is at TDC it is at TDC.

 

contray...on a 4-stroke there at 2 points the motor reaches TDC in 1 complete cycle, it's a 4 stroke b/c it takes 4 strokes, 1 up, 1 down, 1 up, 1 down...the cams on the yfz450 will be in the position i said if you are at the correct TDC of the 2 times it reaches TDC.