Topic: 550k Cam chain adjustment clarification

[Nortstudio]

1976 CB550K

I found the post in the FAQ (engine) section about adjusting the cam chain.  I think it makes sense, except for one discrepancy.  I am about to begin my first tune up in the morning, and I need a final word here.

In the manual, Honda makes it seem overly simple, to just loosen the nut, and the screw will turn itself into the correct setting.  Then tighten the nut back up, and voilà (inside-post joke), good to go.

The FAQ section mentioned loosening the nut, and then turning the screw.  Which is correct???  If I'm supposed to turn it, then where to?

Also, turning to the #1/4 15% after top dead center.  Is this "about" 15%, or am I supposed to get an exact measurement?

Thanks in advance for any clarification.

[Frostyboy]

Firstly, it is important that the engine be positioned at 15ºATDC. This is achieved by turning the engine until the spring post on the advancer unit at the 1/4 mark is just to the right of a line from the timing mark on the crankcase.

I adjusted mine the other day by loosening the nut & I did see the screw rotate ever so slightly in the anticlockwise direction. If you want to confirm the the post is not binding in the cylinders, you could turn it clockwise after loosening the nut the re-tighten the nut. Then, without a screwdriver in the screw loosen the nut & you should see the screw rotate anticlockwise by itself. When it stops, the adjustment is correct. Tighten the nut just enough. Apparently many heavy hands have ruined many an adjuster.

I think a lot will agree that the procedure in the manual is the way to go.

Cheers.

[Nortstudio]

Frosty, thanks so much for the response.

From the photo you included, it looks like there is a tick mark at the 15 degree ATDC.  Is that right? That would certainly help .  Unfortunately, none of my downloaded manuals have photos good enough to see the actual letters/markings in the photos. 

I will stick with the manual's procedure, and maybe check it as described.

Wish me luck!

[Nortstudio]

Actually, after rereading your response, I realize you are not talking about a tick mark, but lining it up based on the spring???  If I rotate the engine until I am just past the "T" mark, this should be correct?  Would have been sweet if there was a tick mark for this - but why make it easy?

Considering that the Honda Manual says to clean the residue from cleaning the points with "a business card" i guess I shouldn't be surprised!

[bryanj]

You should not turn the screw with anything as it is there to assist on rebuild only if you do you can force and damage therack gear inside.

Instead of the 15 deg method use a spanner on the big nut on the advancer and put weight on it so you are just about to turn the engine over clockwise and whilst this tension is applied loosen then re-tighten the 10mm locking nut

This puts tension in the front cam chain run allowing the tensioner to adjust out all the play in the rear run

[tango911]

i see,  so your turning the engine just enough to get all the cam chain slack to the adjuster side right?

[Nortstudio]

You should not turn the screw with anything as it is there to assist on rebuild only if you do you can force and damage therack gear inside.

Instead of the 15 deg method use a spanner on the big nut on the advancer and put weight on it so you are just about to turn the engine over clockwise and whilst this tension is applied loosen then re-tighten the 10mm locking nut

This puts tension in the front cam chain run allowing the tensioner to adjust out all the play in the rear run

Thanks Bryan,

So to be clear (or INCREDIBLY paranoid , I should have my friend put a bit of pressure on the nut inside the plate, while lined up near the 1/4 TDC, and when the pressure feels as if it's about to turn over, that's when I loosen the Cam adjustment nut, and let the screw fly on it's own, then tighten the nut back up.  All this time, said friend should be holding the pressure on that spot just before turn over?  Don't let off until I am done tightening the nut?

Thanks so much.  Sorry to be a pain here, but this is the first time.  I have been assured that once I have done all these tune-up procedures, it will come much easier.  It will be then that I will be able to start helping out other noobs like you all are helping me now.  

I can't wait for that day!!!!

[Nortstudio]

Just followed bryan's method, got it lined up, released the nut...and nothing. The screw didn't move at all. I stuck a screwdriver in there and tried, ever so slightly to see if it would move one way or the other. Nothing.

Is it possible the screw is frozen in place?

Any suggestions?

Thanks a ton

[Deltarider]

Don't expect to see anything. Adjustment is sometimes minute.

[Nortstudio]

Thanks. I moved on to the valves.

Hope it was ok.

[bryanj]

You got it! movement is minimal but do try a few times with the crank in different possitions

[Nortstudio]

You got it! movement is minimal but do try a few times with the crank in different possitions

Should I go back and do it all over again?  Will this effect the rest of the tune-up I have moved onto?

Thanks.

[bryanj]

Do it as many times as you feel like it won't affect anything else

[DavePhipps]

Thanks. I moved on to the valves.

Hope it was ok.

YAY! Now you're on your way to a happier bike. Good progress.