Cam chain play value

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Apr 7, 2008
I was working to adjust the cam chain play, probably not been done for very a long time.
I measured the play to be way exceeding the 3/16" (4,7 mm), actual play was 6-7 mm measured at different positions of the chain. And yes, my timing mark was not stable adjusting ignition with a strobelight.

I got a bit confused when the manual stated "adjust the cam chain to "maximum" 3/16" play.
I think this can be interpreted in different ways, are you supposed to adjust the chain to 3/16 at the tightest position having a larger play at other locations, or is it supposed to be a maximum at any position leaving it tighter at other locations?
Is there no recommended play you should go for??

I would appreciate your comments!

I'm sure the experts will chime in here, but I usually measure deflection in the center of the non tension side.
As you turn the motor the top run of the timing chain will go tight as the cam lifts a valve then slack as the valve closes pushing the cam round.

I just turn the motor or cam until the top run is tight, then take all the slack out of the bottom run by lifting the tensioner with my thumb. Hold it there firmly but not with a lot of force and lock it up. Finally turn the motor over a few times to check the tension in various positions. 3/16" max total movement at the slackest place, but not bow tight.

Hope this helps
Forgot to mention the cylinder head is off so there is no resistance from any valve springs. And this is an MK2A engine with no automatic tensioner.
I thought that the tensioner was supposed to take a portion of the slack and the measurements should be taken on the middle of the top run of the chain with the tensioner "active"??

I wouldn't worry about it too much, if it's too tight the chain will stretch after the first few hundred miles or so. LOL

All jokes aside, Here is a quote from the 72 manual (750):
" 8 - Fit the chain tensioner, fan disc washers and nuts moving the tensioner blade up to give a maximum 1/8th" (3.17mm) up and down movement at the tightest point of the chain and nip up the tensioner securing nut. Before finally locking up these nuts, rotate the crank a little at a time, checking at each stage the chain tension lest there should be a tight spot on some point of the chain."
My interpretation of this is that the tightest spot of your chain should have 1/8" of slack.
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