Quick question about engine timing

[vtrmike]

Hey guys. Just have a question or 2 about engine timing. Have the bike apart and am installing manual cam chain tensioners. Rear one is done, went fine. Lined up the flywheel marks with the inspection cover mark. (tdc on compression) Checked the marks on the cam sprockets and they each are perfectly lined up with the edge of the head. Started working on the front cylinder. Turned the flywheel to the FT mark, tdc on compression. Cam lobes are pointing away from each other.....but when I check the marks on the cam sprockets they look to be both off. The exhaust cam mark is a few mm above the edge of the head and the intake cam mark is a couple mm below the head. To these need to be adjusted? As in take the tensioner out and lift the chain the turn them until the marks line up?? I am confused. Also a quick question. When lining up the fly wheel mark with the inspection hole mark, am i supposed to be lining it in the middle of the RT and FT marks or do i line it up with the dash thats right under the letters. The manual shows in the middle. ANY help with this would be appreciated as I have the bike all apart and would like to get it done, and properly. Thanks.

[8541Hawk]

It is common for the timing marks on the cams to not line up exactly. As long as it is less than a tooth...which it a lot farther than a couple mm, so you should be good.

For the marks on the flywheel, you are looking for the line under the "T" in FT or RT.
Just make sure you are not on the "F" line which is for checking the timing while idling.

[tony.mon]

You can only set it to the the nearest cam sprocket tooth to lined up, without some complicated work slotting the sprocket mounting holes and timing each cam with a dti.
It makes little difference to performance.

[vtrmike]

Thanks for the replies. Its only off a few mm, i assume one tooth on the sprocket would be more then 3mm. Ive noticed with the auto tensioner i just took out that when I rotated the engine the chain tension was pretty constant. With the manual one in, it seems to go slack and tight and slack and tight with i roll the engine over. Is this normal??

[tony.mon]

As you rotate the engine, the crank pulls the cams round, and there is more resistance as the cams act to depress the valves. Cam chain tension adjustments should only be done with the engine on the correct FT or RT mark, when there is no tension on the chain.

[sirch345]

Just to follow on from Tony's reply.
The original (OEM) CCT's being automatic adjusters self adjust to take up the slack in the cam chain whereas manual CCT's cannot, hence why you noticed the slack in the cam chain at certain points as you rotated the engine by hand.

Chris.

[vtrmike]

alright well all is installed and i have rolled the engine over a bunch and the timing seems good. Honestly these manual chain tensioners are a pain in the ass. Im literally considering doing the stopper mod to my almost new automatic tensioners and putting them back in. When I set the chain slack at TDC on compression at like 7 mm, then roll the engine over, there are other places where the chain is wayy more loose then 7mm. If i line everything back up its at 7mm. I thought tdc on compression was supposed to be the slackest point in the chain? I dont get why it goes zinging tight then loser then the set 7mm.

[tony.mon]

Something's not right here. Setting the tension at compression T mark should give you the slackest point, the chain should not become more slack than it is at that point.

Suggest you don't try to start it until you get to the bottom of it.

You didn't damage the chain, did you? trying to rotate the engine while a cam chain is wrapped around the crank sprocket can cause stiff links.

[vtrmike]

Did not damage the chain. It always turned smoothly. No idea whats going on. Rolling it over it seems the slackest when the cams are pointing away from each other and angled downward. No idea why. work on cars everyday and have had 5 bikes before this one. Never had so much trouble with something easy.

[AMCQ46]

Did not damage the chain. It always turned smoothly. No idea whats going on. Rolling it over it seems the slackest when the cams are pointing away from each other and angled downward. No idea why. work on cars everyday and have had 5 bikes before this one. Never had so much trouble with something easy.

Can't be sure if it is right, but there may be a point when both cams are being pushed in opposite directions by their contact with the valves/springs and this will take all the tension out of the top section of the chain (between the cams).

That might be why it looks more slack then. As I said, this is a theory, I have not taken the covers off mine to check if it is fact.

[tony.mon]

I don't think that I've actually measured cam chain slack anywhere other than at compression tdc. There's no reason to do so, so it could happen with all of them... but there's no logical reason for this to occur.

Does it happen on both cylinders?
If only one, then it's possible that a cam is distorted, or a cam sprocket is out of round, but TBH, I'm running out of ideas on this one.

When you say it gets slacker than the approx 7mm, what measurement do you get?