Couple questions . . .

[Don]

Still getting used to my "new" (to me) '79 - Had never ridden a CBX until I bought this one just a few weeks ago, and haven't ridden any motorcycle for the past 15 years or so.

I noticed when I first start it up after a day or so, the voltmeter reads really low (10 to 11 volts) at idle - Even at a fast idle (2500 RPM or so) It stays this way, even for several minutes, until I ride away, and get up over a sustained 3500 to 4000 RPM, at which point it begins charging normally, and then maintains about 13.5 volts. Once the battery is back "up" (after 10 or 15 minutes of riding) the voltage stays up even at idle - Just falling off to 12.5 to 13 I'm "guessing" this is just the alternator clutch slipping when the alternator is initially under a heavy load at low RPM - Goes away completely after the bike's warmed up, and the battery's back up to full . . . . . Normal??

On deceleration, the exhaust (Kerker 6 into 2's) has a good bit of "burble" - I guess that's what you'd call it. Definitely not any kind of backfire. Sounds kinda neat, actually . . . . . Normal??

I think it's in a pretty good state of tune, as it pulls very strongly at all RPM's, and has no sign of a flat spot anywhere. Starts instantly, even when it hasn't been started for several days. Great throttle response too - Crack it just a little at any RPM in any gear and it's INSTANT acceleration. Idles great too, at any RPM I set it to, once warmed up.

There is a good bit of engine chain noise at idle, most of which all goes away by 2000 RPM, but you can still hear (or feel) the big Hy-Vo, especially if you crack it open hard at lower RPM's - The engine doesn't lug then by any means, but you can really feel the chain working under the load . . . . . Normal??

As I said, still getting used to it - Need to get the old, weatherchecked, hard as a rock, Metzler off the back before it kills me. It has a bad habit of "stepping out" especially under tight, off camber corners - Even modest corners. Not used to riding any bike again after so long, let alone a 600 pound "dirt bike" - I'll be glad when my new tire comes in, and hopefully then it'll stay planted. Still, it's reassuring to feel it let go and be able to feather it back under control - Makes your heart go "pitty pat" for a second, and then brings a big smile to your face . . . . ;) Wish I'd bought one of these sooner . . . . . Probably could have got it for a little better price a couple years back too ;)

Don

[cbxchris]

You probably need to take off the valve cover and manually adjust the tensioners...they get stuck. I have seen also where the big hy-vo tensioner fails in the bottom end on high mileage bikes that have been abused. The exhaust you hear is probably normal. BTW some of the noise you hear at idle could be the clutch basket which can be helped with the carbs getting a good sync job.

[HondaCBX6]

I would agree with Chris. Go in and check it. While you have the cover off, check the valves. There is also the Oldham couplers. Replacing worn ones with new replacements can really quite things up.

I would also pull the alternator off the bike. Very easy. Three bolts. Then you can have a look see at the plates and brushes. Clean it up while it is off. There are a few tricks you can do to help the clutch slip. A backing washer added can help allot. I have heard of stronger spings somewhere. You can have you plates resurfaced or ordered a set of plates from Honda. Both the "A" and "B" clutch plates cost ~$96 from Waynesville Cycle. ~$105 delivered.

Honda only has 34 more sets of these! I am going to replace my old ones with new and resurface mine for the future.

PS Don't FORGET TO TURN OFF THE GAS PETCOCK EVERY TIME YOU SHUT OFF YOU BIKE! Bad things can happen if you don't! Fuel will flow from the #6 carb over and into the #1 intake. Filling the cylinder with fuel. You will go to start the bike and end up with a bent rod! OUCH! Something about the angle of the bike on the side stand and the angle of what you park on.

[Jeff Horta]

Don,

It is entirely normal for the voltmeter to read low for a short time after starting the bike, N-O-R-M-A-L in a perfectly working electrical system. What I did notice is that in your post you did not mention any noise associated with this condition. If your alternator clutch is slipping you will hear it as a very distinct metallic clicking sound.

From what I've read in your post, all is well.

[Jeff Dean #4112]

That "burble" you hear when off the gas, it sounds to me like the air cut-off valve is leaking/torn.

[cbxal]

I am having similar problem. Is it easier to remove the three long bolts to get to the plates or the short ones ?

[Don]

I am having similar problem. Is it easier to remove the three long bolts to get to the plates or the short ones ?

On the alternator?? You take out the three long ones, and the alternator comes off all in one piece.

I'm 98% sure mine's slipping, and it's quiet as a mouse - I don't see why it would make any noise slipping with all the oil that's pumped into the inside of the clutch. The clutch plates look pretty worn to me, so it's been slipping - That much I'm (pretty) sure of

It's not a "problem" right now, but I'm gonna change it soon.

My voltmeter doesn't just read "low" - It's VERY low (as in 10 to 10.5 volts), until I get it up to 3K or so

Don

[cbxal]

What should my volt meter read at cruising speed around 4 or 5 thousand rpm? It never goes above 12. Also, If I remove the alternator how can I tell if the plates are getting the correct amount of oil and if that is what might be causing the charging problem ? Thanks.

[Don]

I'd measure the voltage right on the battery with a good voltmeter before I did anything else - Some CBX's are know for having voltmeters which read VERY low, when in fact the charge voltage is much higher.

At anything over 4000 RPM you should read over 13 volts. 13.5 to 13.8 would be about perfect. - If you have that at the battery, you might think about replacing the old voltmeter, or possibly cleaning up some contacts - I wouldn't mess with the alternator if you get a charge voltage measured at the battery of 13 volts or more - That's proof that it IS charging.

Don