Cam Chain Adjustment

[NobleHops]

Www.cbxclub.com/manuals

[martini]

I think the answer is loose.

Is replacing a short timing chain demanding job for a beginner?
What about replacing the long cam chain?

[tevan]

If you have an actual Honda service manual and be very careful it can be done. The long one that goes all the way to the crank you will to split the cases. Major

[bobcat]

I think the answer is loose.

Is replacing a short timing chain demanding job for a beginner?
What about replacing the long cam chain?

Why the need for replacement ? Mileage ? The short chain is the least likely
to need replacement but probably the most frequently changed because it's
a relatively easy job. The long "A" chain is most likely stretched/worn chain*
that would need replacement. If you tackle either job, don't buy a cheap chain.

*Keep in mind that the loading on the short chain (compressing 12 IN. valve springs
and rotational accel./decel of one cam) is less than half of the loading on the long
chain that operates all 24 valves and both cams/sprockets and has 3 wear/contact
points, the crank and both sprockets.

[martini]

The short camchain rattles a little. I'm not quite sure how to adjust the chain tension. See pictures where the machine is rotated clockwise and counterclockwise. I do not know the actual mileage, maybe 34000km...or less..
I do not know if changing the chain is even necessary. Any ideas ?

[daves79x]

The shop manual gives Honda's way, but since you have the valve cover off, there is a better way. Loosen the front tensioner bolt while holding forward tension on the crankshaft. This will put all the slack on the bottom where you want it. See if you hear a 'snap', and/or see movement of the tensioner, it's working. Snug up the bolt and nut, but DO NOT overtighten or it will strip. Replace the o-ring on the bolt (or nut if an '80-'82) if you already haven't. If you see no movement, keep the bolt loose and try to force the bottom run of the chain downward with a wooden or plastic dowel. You should be able to deflect the chain downward quite a bit. This will insure that the adjusting rod is not frozen into the front tower.

Dave

[steve murdoch icoa #5322]

Thanks for those tips/reminders, Dave.

[martini]

"..This will insure that the adjusting rod is not frozen into the front tower."
I also suspected that the adusting rod is stuck into the front tower. The bike has been in the garage for years (20-25 years) before I took it for riding. Thank you for the very clear instructions !

[Jeff Bennetts]

Also if you suspect the tensioning rod is frozen you can give it a light tap with a light mallet using a wood dowel while the snug bolt is loose, preferably a small plastic mallet. When someone here mentions a light tap, it’s just that. Never muscle anything on a CBX motor, nut, bolt or accessory!

[bobcat]

The long chain "A" has been replaced at some point. Note that the link plate pattern
is different. The short chain "B" the plates are separated, The long chain plates are
paired (sandwiched ?) and not OEM. I don't know that it's any stronger but I wouldn't
go the trouble of tearing the motor down to replace it. What's important in a replacement
chain is the pin dia. The original OEM chain has 3mm pins. A good replacement chain
should have 2.7mm pins (more plate surface area around the pin, stronger plates).
In Hyvo type chains, the plates are the weak point at the pin hole, not the pins.

Too much off topic info ?

In the last picture, the chain does appear to sag a little; loose.

[martini]

It's good that someone in the cbx club can analyze whether the chain is original or a spare part.
A couple of pictures of a short chain, with one turning the machine clockwise and the other counterclockwise.
I notice that pictures help to understand the matter.

As Jeff Bennetts mentioned that the tensioning rod is possibly frozen so I'll start with checking it.