Topic: CB500K1 Cam chain adjuster

[toucheturtle]

Hi all,

Decided on a little routine maintenance today but as per usual I seem to have just created a whole world of misery for myself. Adjusted tappets on my CB500K1 and fitted new plugs, before running the bike again thought I'd re-tension the cam chain adjuster.

When I fired the bike up it made a horrible rattling sound on idle and low revs which seems to go away as you increase the revs. The adjusting screw slot is in the horizontal position, is it supposed to be vertical? See photo

Have tried turning the screw but doesn't seem to want to turn more than 45 degrees clockwise. Went through manual procedure of setting crankshaft advancer assembly at 15 degrees ATDC but seems no movement in adjustment screw. I am not aware of damaging anything but does sound like a bag of nails now.

Any advice greatly appreciated,

Andy

[spitcrazy]

Sounds like you set the screw too loose. You don't need to adjust the screw.

There is a youtube video on how these work, it's complicated to visualise how these tensioners work. The screw is attached to a cam gear that moves a spring loaded rack of teeth. You don't need to turn it, just make sure it's free to turn, it should only move a quarter turn....that means it's working correctly. The springs do all the work here for you.

But don't worry, set the timing mark, loosen the nut, the screw finds the right position automatically. Just make sure it is moving freely it should be somewhere in the middle of it's range of motion, not at either end of it's range. Tighten the nut with fingers, just snug. Use a screwdriver to hold the screw in position and tighten the nut, not crazy tight just snug so it holds. That's all there is to it.........almost.

Experienced mechanics on this forum have said for best results set timing mark and begin rotating the crankshaft until the engine is fully in compression, in other words, just before it's about to go over and THEN tighten the nut. This makes sure all the slack is against the adjuster. No slack is left on the other side of the chain. Stop and think about it: the crank drives the chain, clockwise, turning it gathers ALL of the slack on the frontside and moves it to the backside where the tensioner is.

Hope this helps, video below:
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