Topic: "Cam Chain adjustment made easy" "or is this bad advice??"

[750goes]

Reently talking to another enthusiast not a member of this forum (don't think so anyway), and we got to talking about noisy cam chains and all the effects they have on engine performance.. here I was being fed I thought a bit of BS but that happens.. I'm pretty gullible when talking about these bikes, I'll listen to anything.. and read everything..

He mentioned that to cure the excess cam chain noise and the slack from a cb750 was really simple (had me by the short and curlies right then),

I quote - not verbatim, but from my scribbled down notes

"Get engine warm from running",
turn it off
remove points cover
undo the lock nut on the cam chain tensioner and back it off a few turns,
then from the points cover - removed earlier - turn the big nut counter clockwise or in backwards rotation just a bit (suggestion was for a 1/4 turn)
this is the point where he believed that any chain slack would be picked up by the tensioner readjusting.
then just tighten the bolt and then the lock nut
job done???
he reckons no more noise..

I have not tried this as my bike is in the very primary stage of stripping/cleaning/fixing broken thingies, but I would ask the oracles lon this site if they could shed some light or information on this method, and or if this is indeed BS or could it work???

I dunno whats the learned opinions ??

[Bob Wessner]

Check the "Engine FAQ's" I'm sure there will be something there on this.

http://www.sohc4.us/forums/index.php?topic=369.0

[Bodi]

Close but no cigar.
You're turning the crankshaft with that nut. Running, it turns clockwise and pulls the cam chain down at the front to turn the cam.  The adjuster is at the rear of the chain path and takes up any slack on the chain's return run back up from the crank sprocket to the cam sprocket. If you loosen the adjuster and turn the crank backwards you will pull the back side tight and push the tensioner out, and make slack on the front side. This maximizes chain slack - opposite what you want.
The process is reaonable if you turn the crank in the running direction.
BUT: the valvegear involves powerful springs pressing the followers down onto the cam lobes - and that will make the cam try and rotate. There are points on the cam rotation where the balance is towards tightening the chain at the front (i.e. more of the 8 rockers are pushing back than are pushing forwards) and points where the balance is slackening the chain. The Honda procedure of doing it while running should ignore this static balance, the procedure of setting the cam at a certain spot is so the springs will be rotating the cam so as to put any slack at the tensioner.

[750goes]

Bob,
thanks for your response, I have read nearly all posts on the cam chain tensioning processes, and have copies downloaded of some manuals that will assist me when the time comes..

Bodi,
thanks for your response, the adjustment information I have read for the 750 has all been to do the adjustment when the bike is NOT running, I read a few articles on other models being adjusted while running but not the 750 ??

what is right running or not ?


thanks again

[8 Track]

Bodi,
thanks for your response, the adjustment information I have read for the 750 has all been to do the adjustment when the bike is NOT running, I read a few articles on other models being adjusted while running but not the 750 ??

what is right running or not ?

Now my curiosity is peaked too.  I have already adjusted my 750 the static way, as outlined in a maintenence manual.  But I went one step further and gave it a little push.  It is explained to rotate the engine manually and feel the tensioner go in and out.  Anyway, I didn't really feel any movement and I don't think I pushed it any farther than the spring already did (I have calibrated hands).  I marked my small drill bit I was using and I think I got an extra 1/64 out of the deal; hardly worrying about!  Besides, if you push it in too far, but then let up before you lock it down, no harm done, right?  Geez, my mind is my worst enemy!  Eh, the bike sounds fine.

[750goes]

2strokecrazy,

I have read that somewhere else about turning over manually and feeling the tensioner move in and out, then you try to locate the adjuster at the point of its maximum inward movement. then lock it down.

Then  other adjustments if required are performed after this like
tappetts, points, timing - not sure of the correct order..
but all timing/tuning matters are affected somewhat by the slackness/tightness of the chain

anyway all info stored for another rainy day
its 37C in Sydney today, humidity 90% air con running over time

thanks

[Jughead]

OK this is According to my 78 750F owners Manual
#1 Start the Engine and set Idling speed to 900-1100 RPM
#2 Loosen the Tensioner Lock Nut and The Tensioner Bolt.When these are loosened The Cam Chain Tensioner wil lAutomatically Position Itself to Provide the Correct Cam Chain Tension
#3 Retighten the Tensioner bolt and Lock Nut.

[8 Track]

its 37C in Sydney today, humidity 90% air con running over time

thanks

It got up to around 37 degrees the other day here too, but that's farenheit.   

[8 Track]

OK this is According to my 78 750F owners Manual
#1 Start the Engine and set Idling speed to 900-1100 RPM
#2 Loosen the Tensioner Lock Nut and The Tensioner Bolt.When these are loosened The Cam Chain Tensioner wil lAutomatically Position Itself to Provide the Correct Cam Chain Tension
#3 Retighten the Tensioner bolt and Lock Nut.

I wonder if mine being a 76 k6 matters...  I'm going to leave it alone!  It ain't broke!   

[750goes]

mine is a k6 in an f1 frame or something like that..depends on what day it is as to what i call it, doesn't matter, she don't answer back (the bike i meant)

time for a beer.. new years eve all the best

[Jonesy]

According to my manual you do all this with the engine off. I've tensioned mine this was and it seems to work very well.