Topic: Best way to adjust cam chain?

[rk]

The manual gives me two ways to adjust the cam chain, one static, one running.

The running one basically has you loosen the nut and bolt... and then re-tighten it while the engine is running.

Has anyone used this method? Is there much of a trick to it?

[bryanj]

Ignore both!

As a dealer Mech in the UK for many years the most reliable way is to loosen the locknut(and bolt if 400 or 750) put weight on the kickstart so that the engine is just about to turn thus pulling the front run tight and putting all the play on the tensioner side then whilst holding the kickstart nip up the bolt and nut.

If this doesn't cure a noisy chain either the chain or the tensioner need replacement----Frequently both

[ncstatecamp]

That's awesome. Gonna have to try that.

[rk]

Awesome, thanks!

[Duanob]

The running method works great for me. Use a tiny bit of counter-clockwise force on the adjustment screw.  I can tell when the chain is quiet before tightening the lock nut.

[lucky]

The manual gives me two ways to adjust the cam chain, one static, one running.

The running one basically has you loosen the nut and bolt... and then re-tighten it while the engine is running.

Has anyone used this method? Is there much of a trick to it?

WHICH HONDA?? They are all different.

Do not adjust the CB750 with the adjustment loosened unless you want to rebuild the engine because you bent a couple valves.

Just follow the workshop manual.
NOT internet.

[74750k4]

"put weight on the kickstart "

Great suggestion!

[exf5003]

Ignore both!

put weight on the kickstart

If this doesn't cure a noisy chain either the chain or the tensioner need replacement----Frequently both

Hey Lucky, would you say this works for a 74' 750?
Sounds like it could be an easy trick... 

[Schnell]

Weight on the kickstand:    +1

Edit: oops, that should be kickstart

[bryanj]

Duanob, putting any tension on the screwdriver slot on a 500/550 is the easy way to wreck the tensioner mechasim mate

[Nic]

Weight on the kick starter, +2

[lucky]

Ignore both!

put weight on the kickstart

If this doesn't cure a noisy chain either the chain or the tensioner need replacement----Frequently both

Hey Lucky, would you say this works for a 74' 750?
Sounds like it could be an easy trick... 

If it is a 1974 CB750 The first thing I would do is check the sump screen for bits of rubber.
If it does have little bits of rubber that means the cam chain tensioner rollers are coming apart. Those little bits of rubber can end up all through the crank shaft journals. They are 35+ years old unless they have been replaced.

Clymer's workshop manual Page 48.
The cam chain on the CB750 is set with the engine is off and the crank is set at 15º ATDC .

Just buy a manual.

Stop listening to internet guessing.

[Schnell]

But there are some pearls of wisdom out there. This may be one.

[bollingball]

Weight on the kickstand:    +1

Kickstart I think it was just a typo

[bollingball]

The manual gives me two ways to adjust the cam chain, one static, one running.

The running one basically has you loosen the nut and bolt... and then re-tighten it while the engine is running.

Has anyone used this method? Is there much of a trick to it?

WHICH HONDA?? They are all different.

Do not adjust the CB750 with the adjustment loosened unless you want to rebuild the engine because you bent a couple valves.

Just follow the workshop manual.
NOT internet.

Would you tell me how you can adjust it without the adjuster loosened? I don't understand.
Ken

[TwoTired]

Just buy a manual.

Stop listening to internet guessing.

That's rich. (Considering the source.)

Now you recommend ignoring a Honda shop mechanic?

Bryan's suggestion/advice has real merit, imo.  Think about it.

Do you recall what the manual says about setting point timing?

[Schnell]

Right. Kickstart!

Bollingball, I think a previous piece of advice was not to loosen the cam chain adjuster with the motor running.

[bollingball]

Right. Kickstart!

Bollingball, I think a previous piece of advice was not to loosen the cam chain adjuster with the motor running.

Perhaps, he did not say anything about the motor running or not. So I did not get it I see now.

[lucky]

Reply#7

"The cam chain on the CB750 is set with the engine is off"

[AndyH]

Ignore both!

As a dealer Mech in the UK for many years the most reliable way is to loosen the locknut(and bolt if 400 or 750) put weight on the kickstart so that the engine is just about to turn thus pulling the front run tight and putting all the play on the tensioner side then whilst holding the kickstart nip up the bolt and nut.

If this doesn't cure a noisy chain either the chain or the tensioner need replacement----Frequently both

Dragging this out of the dim dark past!     So the position of the crank is of no consequence if this method is adopted?
That is, disregard the 15° ATDC position  (more difficult to determine as I have a Dyna S).

[PeWe]

No problem with too stretched chain?  Heavy deceleration with gearing downs....

[AndyH]

No problem with too stretched chain?  Heavy deceleration with gearing downs....

[evinrude7]

Do you get the kick start to a point of tension while adjusting or do you actually have to keep pressure on it via person #2 while adjusting?

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[PeWe]

...but a rattling cam chain is definitely not too stretched I had a discussion with other CB guys last week about adjusting the cam chain.  One guy loosen the screw and turn engine around and tighten it. He said that too tight is not good either.

I have always, since my first attempt to follow the manual which say loosen tensioner screw at idle and it will adjust automatically, used the kick while I have a screwdriver, allen tool stucked into the end of the tensioner housing to see when it is in the deepest position which will take some kicks. Here lock the screw and nut.
The automatic procedure might work with a harder spring. My bike had only max 20.000km back then when I tried the recommended by Honda procedure.
No problem for me with kick and deepest position.

While talking about chains... same guy mentioned a case he is involved in (repairing the engine)...one guy geared down too heavy from 3:rd to 1.st gear and the primary chains broke, blew the cases, crank etc etc. I think this was more or less a race CB750 SOHC engine. I do not know if the chains were heavy duty chains or only the Honda OEM primary chains.

[evinrude7]

i'm thinking of giving this "while running adjustment" a shot before i head out for a quick job in the am.  get the bike idling, warm and loosen the lock nut and bolt then just cinch it back up?

edit: if it doesn't quiet down i'll do it the way uk honda mech recommends.