Topic: CB550 Cam chain adjuster replacement

[Whammo]

Hello all,
I’m 90% sure my cam chain adjuster needs replacement or at least repair. The lock nut is indeed “locked” onto the adjusting screw. So far, no amount of force or penetrating fluid or heat has been able to break it free...even with 2 people grunting and twisting. All I’ve managed to do so far is ruin the head of the notched screw. Also, and probably more importantly, the screw spins freely with the nut attached.
Does anyone have any last-ditch suggestions for freeing the locknut before I resort to dremel-ing it off?
In preparation for its removal, I’ve taken off the carbs and exhaust, but have found little info online of exactly how deep I need to go to remove the adjuster.
Also, what precautions should I take if the head needs to come off to retain the correct timing on the cam?
I’ve only had the head off of a bike once (an ST1100), and the results were less than optimal.

Thanks in advance for any info.

[craz1]

The 74 cb550 Im working on had a wonky adjuster also. If the adjuster is turning freely it's probably broken or damaged the teeth on the adjuster. Its not a very good design. As far as the nut, if it's rusty try a dab of the Works bathroom cleaner. it will dissolve that rust overnight. Just dab it once in a while throughout the day with a cotton swab.

[bryanj]

The design is fine its miss use that wrecks them. Al 500 four and 550 four are the same so used are out there and Dave Silver sell repos but not cheap

[craz1]

Yep I had to order one for my CB550. The design is just a stamped piece of steel so yes you have to be careful when adjusting your cam chain. The design wont take much torque to screw it up.

[flatlander]

well once you loosen the nut, the spring mechanism adjusts itself. you're not supposed to torque that screw at all. if you use it properly it's fine.
but yes, if you think you have to manually tighten it then you might overdo it and mess up the screw.

replacing the adjuster is not totally straightforward. you'll be taking off the head and lifting up the cylinders a tiny bit to make the adjuster slide down and seat in its proper place in the case (can be best checked with the oilpan off). then guiding the screw through its hole in the cylinder as you put it back down.
because you'll move the cylinder, you should also replace the base gasket.

[Whammo]

Appreciate the info.
Does anyone have a link describing the actual process of tensioner replacement, if one exists.
Thanks.

[goodtryer]

Page 25 in the manual: http://manuals.sohc4.net/cb500/service_manual/HSM500550_2.pdf