The International CBX Owners Association

If you set the cam chain tension as per manual, just by undoing the 10 mm chrome dome nut on the back of the cylinder barrels, and re-tightening it, if the tensioner itself is sticky (not at all uncommon), it may not have done very much adjustment at all and the chain could still be quite loose, hence you may still have mysterious internal rumblings.

I find it best to set the cam chain tension with the cam cover off and follow this process. A second pair of hands holding a torch (or wearing a head torch) helps. [That's flashlight, or similar,for you blokes north of the dividing line. (ed)]

Remove both cam cover and RH crank end cap.

Take a 17 mm ring spanner and slowly rotate engine forward (clockwise) while looking down the front run of the long A chain that runs from crankshaft to exhaust cam. You will see the run of the chain pulled very tight as the crank 'pulls' down on the load of turning the camshafts. All the slack in the chain will be moved to the rear run of the chain.

Now turn the motor backwards slightly and you will see all the slack now move to the front run of the chain. (Doing this just to share the principle of removing slack).

OK, now loosen off the 10 mm chrome dome nut on back of barrels a few turns (don't take it all the way off).

Now put as much forward rotational pressure on the 17 mm spanner as necessary to move all the load onto the front of the cam chain. Just enough for the crank to be pulling down on the chain, but not enough to actually rotate the crankshaft.

While holding that forward rotational pressure, on the end of the crankshaft, now push down very firmly with your thumb on the rounded very top part of the 'A' tensioner, so that it bows down and in towards the crankshaft and takes up all the slack in the back of the chain. While pushing down on the top of the tensioner, now tighten the lock nut so that it is just firmly nipped up - ie; not too tight.

Now when you slowly rotate the engine backwards just a little, you should have much less slack in the chain.

For the shorter B chain, undo the lock nut and pinch bolt on the front of the cylinder head. Now push down firmly on the bottom run of the chain and then release the downwards pressure. The tensioner should bounce up and down freely and you will observe the rod on the front end of the tensioner sliding in and out of the hole in the cylinder head.

By slightly rotating the crankshaft back and forth, you will see the slack in the chain move from the top to the bottom runs of the chain.

So, once again, holding that forward rotational pressure on the end of the crankshaft, the tensioner should automatically spring up to take all the slack out of the bottom run of the short 'B' chain. While holding that forward rotational pressure on the crankshaft, just nip up the pinch bolt on the front of the cylinder head, then do up the lock nut. They just need to be nipped up firm. Not too tight at all.

If, after doing this, you still have noises coming from the middle of the rocker cover, you may be up for a set of oversize Oldham coupling joints to join the pairs of cam shafts

Great content as usual Tony, thank you so much for another excellent contribution.

N.

Nice write up Tony! That is exactly how I do mine! I love KNOWING that the chains don't have any slack in them. The book method does not leave me with that warm and fuzzy feeling of knowing they are tensioned.

Steve

Cam Chain: I did adjustment according to your instructions but i'm just worried that i didn't over tightened it, is this even possible? I think that B chain is possible to make too tight.
I loosened front adjuster lock nut and bolt while holding down forward tension and re-tightened the bolt and lock nut. B chain now seems very tight, no slack at all.
So on tightening the bolt, how far should the bolt be screwed in before locking it in?
A chain has just a tiny bit of slack, i can see it move very slightly, B does not move at all!
Thanks

Using the method as described, it is not possible to overtighten the cam chains, neither the A long one from crank to exhaust, or the B cam to cam chain.

The front tensioner bolt and lock nut simply pinches against the tensioner shaft to prevent the shaft from sliding up and down the hole in the cylinder head.

The bolt only has to be nipped up just firm, no more. Ditto the lock nut. Hauling hard on the bolt and lock nut to make it tighter does absolutely nothing to change the chain tension, and only serves to mung up the bolt thread cylinder head, as many have learnt the hard way.

Pleased you found the adjustment method useful Cross, nice job.

Cheers....Tony

Thank you very much. I loosened things and re tightened and it looks good now.

Worked great! Thanks for the write up.

Pleased you found it useful Sparky. Great to learn and do stuff on these trusty old gals yourself.

And don't forget to put the oil pool plates back in on the Inlet side if you were doing the shims.

Now get out there and ride it like you stole it.

Cheers...Tony

Nice info HerdyGerdy - do you have same info for that mother of all chains - the Crank-Primary Shaft Drive Chain ?

Thanks, Kev

Great write up on the chain tensioner adjustment sir. I am going to tackle that this weekend and just wondered if i need to drop / pivot the motor down, to achieve this job.. Cam cover looks pretty close to the frame ?

Thanks - Kev

Kev -- the valve cover can be removed without tilting. Put some sort of 'cover' over the top of it as you wiggle it out. Otherwise, you will scratch it on something. But, it can be done. Greatest headache is installing it -- keeping the gasket in place. 'Tack' it to the valve cover with honda-bond/yama-bond/Permatex, etc. Don't go overboard. Just tack it enough so that it holds to the cover. You don't need anything as a sealer. You're just using the stuff to stickthe seal to the cover. THEN, finagle it (technical term) back into place. Don't forget to put something over it as you do so to prevent scratching. A bit of a challenge. BUT, better than the engine tilt thing.

Just use painter's tape to protect the valve cover. I'm starting to use this even when I pull the side covers off of the X or the F. Cheap insurance to protect these parts.

That should work. Thanks.

Thanks for kind words Pistonbroke.

To help give you a few extra precious mm of clearance, here's a coupla' tips.

a) undo the front and rear coil mounting bracket bolts and tie the coils up out of the way slightly.

b) put a jack under the motor and loosen off all the engine mount bolts and rear muffler mounting bolts. Lower the jack and you will see the engine sag down slightly, taking up the slack in the mounts.

When done, raise the engine back on the jack and re-tighten to factory torque specs.

Sorry can't help with the mother of all chains, it is tensioned by hydraulic pressure from the pump.

Good luck and let us know how you go.

Cheers...Tony

Thanks for the article, will use the method on my shop recon bike. Good info!