Yz450f timing

[BigBoyBike]

Hello I need help timing my bike. I get it to tdc and I line the cam dots where the manual says and when I put the cam covers back on and push the kick stater down the piston hits the exhaust valves I need help thank you

[The Spanky]

You have to count the cam chain pins between the sprockets.

[billygildark5007]

Are you sure your using the correct index on the flywheel and don't have it 180 degrees backwards?

[nucular]

You should always roll it through by hand a couple times before you button it all up. I would think maybe 180 of like the other poster mentioned.

[BigBoyBike]

Count the pins I got 9?

[The Spanky]

I'f I'm not mistaken it should be 13 pins on that bike from cam timing mark to cam timing mark if the cams are timed correctly in relationship to each other. I don't think 9 pins is even possible.

 

You need to re-check all of your timing marks. If the piston is hitting the valves they are NOT all lined up correctly.

[BigBoyBike]

I've must have counted wrong

[BigBoyBike]

Ok so I recounted mad sure I was on tdc and every timing mark was correct and I got 16

[BigBoyBike]

Even if it's at tdc it could be 180 backwards?

[Hoosier-Daddy]

13 pins between the 12 o'clock timing marks on the cams. Lobes should face out. Timing marks on cams should be at 12 o'clock and the other 2 level with the top of the head on the outside. Make sure the flywheel is on the right mark, There are 2 on my 2009. I'm pretty sure the flywheel needs to be on the I mark not the H.

Are your valve clearances within spec at tdc?

Edited May 19, 2014 by Hoosier-Daddy

[The Spanky]

Even if it's at tdc it could be 180 backwards?

 

 

TDC is TDC. Can't be 180* out, it would be at BDC.

[nucular]

But the mark on the flywheel lines up at both TDC and BDC

[The Spanky]

But the mark on the flywheel lines up at both TDC and BDC

 In your first post you said this:

 

 

 

BigBoyBike, on 17 May 2014 - 5:55 PM, said:

 I get it to tdc

 

 

Now did you verify that it was at TDC or not?

 

And no, the marks don't line up at BDC. You're looking at the wrong mark if that's the case.

Edited May 19, 2014 by Chokey

[nucular]

I am not the OP. I was merely pointing out that the flywheel can line up with the mark even though the piston may not be at tdc. I don't know how it got into the state it's in so it's possible the flywheel was lined up wrong and then the cams aligned. It could also be that he aligned it with the wrong mark on the flywheel.

Edited May 19, 2014 by nucular

[The Spanky]

I am not the OP. I was merely pointing out that the flywheel can line up with the mark even though the piston may not be at tdc. I don't know how it got into the state it's in so it's possible the flywheel was lined up wrong and then the cams aligned. It could also be that he aligned it with the wrong mark on the flywheel.

 

 

If he's looking at the correct mark, it only lines up at TDC.

 

All of my answers have been predicated on his first post, where he stated he had it at TDC. Now we don't know if he did or not, so anything could be possible at this point. He really needs to get someone over there that knows what they are doing to put eyes and hands on to help him through this, we can only do so much through text communication.

[grayracer513]

But the mark on the flywheel lines up at both TDC and BDC

 

No, they don't.  TDC is Top Dead Center; the piston is at it's highest point.  That only happens every 360 degrees.

[nucular]

No, they don't. TDC is Top Dead Center; the piston is at it's highest point. That only happens every 360 degrees.

I won't argue. I have only been in there a couple times but I recall aligning the mark on the flywheel and not being at tdc. I had to roll the flywheel another revolution to be at tdc and have the cams aligned.

[The Spanky]

I won't argue. I have only been in there a couple times but I recall aligning the mark on the flywheel and not being at tdc. I had to roll the flywheel another revolution to be at tdc and have the cams aligned.

 

 

That's because you still had everything together. You were at TDC, just on the exhaust stroke, so the cams were 180* out of phase. Rolling it another 360* put you at TDC on the compression stroke for everything to be in alignment.

 

If the timing chain is not on, you simply align the flywheel mark at TDC, then align the marks on the cams. The pin count is to ensure you have both cams aligned with each other.

[72degrees]

I won't argue. I have only been in there a couple times but I recall aligning the mark on the flywheel and not being at tdc. I had to roll the flywheel another revolution to be at tdc and have the cams aligned.

 

The way I look at it, for cam timing/clearance checking you have to be at TDC on the compression stroke not the exhaust stroke.

 

Edit: I see Chokey already cleared this up. I use a probe through the plug hole on my 450F to find TDC as the trick cover has no inspection hole. Happy memories of setting the ignition timing on magneto Matchless G80s with a spoke and a steel ruler ? 

Edited May 19, 2014 by 72degrees

[nucular]

That's because you still had everything together. You were at TDC, just on the exhaust stroke, so the cams were 180* out of phase. Rolling it another 360* put you at TDC on the compression stroke for everything to be in alignment.

If the timing chain is not on, you simply align the flywheel mark at TDC, then align the marks on the cams. The pin count is to ensure you have both cams aligned with each other.

Yep you are right. I am probably just adding confusion here.