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-   -   World's biggest idiot. Pulled rear CCT while engine at BDC (https://www.superhawkforum.com/forums/technical-discussion-28/worlds-biggest-idiot-pulled-rear-cct-while-engine-bdc-26153/)

Fastforward 07-15-2011 02:20 PM

World's biggest idiot. Pulled rear CCT while engine at BDC
 
Yup. You heard it right. Don't even ask how I did that. Feel free to mock me. How in the world do I go about remedying my screw up?

7moore7 07-15-2011 02:34 PM

More specifics, please!

Fastforward 07-15-2011 02:42 PM

Here's the sequence of events:

- Pulled the seat, tank, airbox, all that good stuff.
- Lined up the RT mark through the timing hole.
- Pulled the rear CCT and heard the ominous "click".
- Looked at the cam lobes and saw they were facing away from each other at about a 30 degree angle downward instead of towards each other.
- Facepalmed.
- Then came in and posted this.

lazn 07-15-2011 02:56 PM

It's not so bad, before turning over the engine at all, follow the cam timing procedures in the service manual. (download from KB section of forum) You may be able to "inchworm" the cams back into place too.

K30 07-15-2011 03:16 PM

The rear cylinder is the one you want to hear the 'click' from, if you had to pick. I had the front go and while I was able to 'inchworm' the timing back to the right spot, it was a PITA due to the location.

Fastforward 07-15-2011 03:23 PM

Can someone fill me in on "inchworming" the timing back to being correct? I've read though the service manual but if there's an easier way to do this I'm all for it. How far out of time would I be having pulled the CCT where I did? Thanks for all the responses guys.

lazn 07-15-2011 03:48 PM

Inchworming the timing involves creating enough slack that you can lift a small section the chain over a tooth of a sprocket and work that slack over the rest of the way to adjust the timing, without having to completely remove everything.

The caveat is that you can't do this when there is tension on the cams from the lobes pressing the valves.. So you might need to get the engine to TDC to do it. This can work for you IF you can rotate the engine to TDC without the valves hitting the piston. (so if the click was only one or two teeth, you might be ok to try this method) But if you are far enough out of time that the valves will hit the pistons then you have to use the service manual method.

Assuming you have both sparkplugs removed, and can freely (and very very slowly) rotate the engine, you can try carefully moving it to TDC (with the CCT in place but only tight enough to touch the chain, no pressure on it) and be CAREFUL because if the valves are going to touch the piston you will have to stop or you risk messing up the valves / valve guides.

edit: 7moore7 has actually had his engine further apart than I have, so follow his advice! :D

7moore7 07-15-2011 03:55 PM

1 Attachment(s)
Well, you have to figure out which direction the timing skipped... I'm pretty sure if you slacken the rear CCT too quickly that it will skip toward the tension, or clockwise. What you do is take the cam chain cover off- there are three bolts holding it on, and you lift up the cam chain and move it counter-clockwise one notch on both of your sprockets.

I'm not exactly sure on the rotation of it, but your cam chain should be taught on the side opposite of the CCT, so you want to adjust it so that this is the case. This only works, like Lazn said, if you haven't really rotated anything yet.

Once you have done that, rotate the crank 360 degrees very slowly (counter clockwise). If it stops, don't force it because internals are bumping. But if not, then look at your cam chain sprockets and make sure that the RE and RI marks both are flush with the surface of your motor cover.

This picture gives you an idea of setting the timing, although the FI is for the front and not the rear like you're checking:
Attachment 25873

7moore7 07-15-2011 04:01 PM

Again, not totally sure on which direction you need to inch the chain back, but when I say counter-clockwise, I'm looking at it from the right side of the bike, where the cam sprockets are closest to you....

Fastforward 07-17-2011 03:33 PM

So today is the first chance I've had to peek at it after posting here the other night.

The way it currently sits is that I've rotated it around so the valves are unloaded. The engine is at RT when viewed through the timing hole. Well, actually a degree or two past but close enough at this point. RI is within a degree or so of parallel with the top of the head. RE is about 2-3 teeth off above the head, not below it.

I'm plenty mechanically inclined but I've never had to time anything so bear with me here. It seems the logical course of action would be for me to get enough slack on the chain so I could rotate the exhaust cam only back counterclockwise until RE is parallel with the top of the head again. Is that what I'm aiming for here or is my thinking wrong? You mentioned rotating the chain over both sprockets but why do that when only one cam is out of time?

lazn 07-18-2011 09:18 AM

you got it right, but do it one tooth at a time, and be careful not to drop the chain into the engine, or to lose the time on the one that is right. Slow and steady. (you might zip tie the one that is correct if that still leaves you enough slack to work on the other one.. But you would have to rotate the engine back and forth to do it that way)

RIPI 07-18-2011 01:17 PM

I hate found it is easier to remove the whole cam than try to deal with removing a sprocket, risking a bolt dropped down into the engine, and more importantly trying to get a torque wrench in there to properly re-tighten. Of course while you are in there valve clearences should be checked also....


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