From: davewi@soccer.wv.tek.com (David H. Wise)
Newsgroups: rec.motorcycles
Subject: Re: CX500..what the hell
Keywords: calumny
Date: 10 Apr 92 22:29:32 GMT
Reply-To: davewi@soccer.wv.tek.com
Organization: Tektronix, Inc., Wilsonville,  OR.

I read this thread with interest, since I one one, and I decided to burrow
into my genuine shop manual and set the record straight.

Preliminary comments.  My manual is part # 6141505, "'78-'82 CX500, Deluxe,
Custom", and the newest pages are dated Oct. 1981.  This manual makes not the
slightest reference to the GL500 Silverwing, or to the turbo models.
What's more, it never mentions the cam tensioner problem.  I got THAT stuff
from my (much-maligned) Clymer, which also handles the GLs but not the Turbos.

Neither manual gives the motor's hp.  What wusses.

Excerpts from what a bunch of people posted, along with my reactions:

>OMIGAWD, the Plastic Maggot is alive and well.

>...but the cheese-ball
>graphics and Bat-cycle headlight/turn signal shroud on the first few
>years production of the 500 make it one of the ugliest bikes of all time.

>Mine was a pristine 1981 Custom (not the "Batcycle" Deluxe) and was,
>IMO, one of the most beautiful standard styled bikes ever.

>In Sweden, the standard CX500 was called "The Water Buffalo" by those who
>liked it, and "The Plastic Pig" by those who did not.

In 1978, there was only "CX500".  Dumpy-looking tank, Bat-cycle headlight.
Early production had a serious cam chain tensioner design defect that
would trash the engine if you let it go.  They fixed it, and all early
units that came in for any service whatsoever were supposed to be retrofitted.

Honda got the hint in '79.  They ditched the headlight housing in favor
of a much better-looking chrome nacelle, moved the turn signals down
onto the forks, changed the tank shape a bit (but it still looked dumpy),
changed the radiator grille from black plastic to shiny aluminum, put on
a new brake master cylinder, and called it the CX500 Deluxe.  Then they
took the Deluxe and put on better-looking mufflers and a snazzy (but
pitifully small) tank, and called it the CX500 Custom.

By 1980 the basic CX was gone, leaving only the Custom and Deluxe.
They added an accelerator pump, and put limiters on the idle screws.
My bike is a 1980 Custom.

In 1981 they went to air-assist forks, added a vacuum-operated fuel petcock,
and a halogen headlight.  On the Custom, they increased the rake and trail.
They also added a second front disk, lengthened the frame,
and called it the GL500.  Add a fairing and bags, and you have the
GL500I (Interstate), known as the Silverwing.  

All this time they used a complicated but reliable solid-state (but no
transistors!) ignition system that used a total of seven different coils
pulsed by the alternator rotor, could operate without battery or charging
system, and had no adjustments at all.  Timing advance was done by having
six pulses of different shapes added and subtracted together to fire the
SCRs that actually zapped the coils.  In '82 they ditched this and went
to a battery-operated transistor system with a mechanical advancer and
manual timing adjustment.  Must have been cheaper.  Full advance with
this system came on at an amazing 2800 rpm, as opposed to 5800 previously.
I'd like to ride an '82 to see how that affected the torque.  They also
added a fuel strainer and went to a dual-piston front caliper.  The shop
manual does not mention a Deluxe model for this year.

In '83, the CX500, of any stripe, was no more.  They bored and stroked it
out to 650, put in an automatic cam chain tensioner (the previous edition
was manual), an electric radiator fan, and a Pro-Link progressive rear
suspension.  Models were the CX650C, GL650, and GL650I.

>The designer's final horrible joke was to include an "interference fit"
>ceramic washer as a seal in  the water-pump.  Instructions for  fitting
>this seal were something like:- [my nightmare, deleted]

No, it has _two_ ceramic parts, one goes in easy, the other -- don't
even try.  Take it to the shop.  They put on special tool #xyzzy and whap
it with a hammer.  Special tool #xyzzy costs twice as much as having them
do the job, and it's special-order besides.

>500 v-twin (watercooled) transverse , shaft drive. Later versions were
>produced with bigger engines (650 I think) and there was even a turbo version.

>The front  suspension was  based on  a sound  (but previously  untried)
>design involving cup-cakes and warm syrup.

>Produced mid-seventies to mid-80s. Very reliable (apart from early problems
>with cam-chain tensioners). Monumentally underpowered. About 200lbs too heavy.
>Very high centre of gravity. Dreadful handling. Comfy seat. Said to make
>a good sidecar bike (pity Miles isn't able to read this, he has one set
>up with a chair and some leading link forks).

>I learned to ride on a CX500 and have since sold it.  The suspension
>is far too mushy, and the CG is too high making the bike dive terribly
>under braking and just generally handle like an undersprung vintage
>standard.  A tad on the heavy side for a 500 at 445 lbs dry, but a
>nice trouble-free mount capable of touring with ease (the Silverwing
>was derived from it - I called mine the RedWing :-).

Progressive fork springs and decent tires help the handling a lot,
but you can't do a thing about CG.  Or weight.

>In addition to this, a model named CX500 E was
>produced. This looked more like a sport-tourer
>than the standard machine did (a little bit like
>a stripped CX500 T, actually).
>By the way, the turbo version (CX500 T) developed
>75 bhp.

Are you sure about the E?  Why doesn't my manual mention it?  I know that
some units had an engine number that started with 'CX500E...', but these
were just plain CX500s with a wierd serial number.

>The Honda CX-500, built 1978-1983 (I think), is a longitudinal V Twin of
>474 cc displacement with 4 valves per cylinder, fed through a pair of (I
>believe 35 mm constant velocity carbs with electronic ignition and liquid
>cooling.  Single disk single piston single caliper front and drum rear
>brakes, shaft drive and UJM styling.

496 cc, 4 valve/cyl.  GL-500s had bigger carbs and dual disks.  '82s and later
had dual-piston.  I've seen several redlines on the net, but mine is 9800.

>Strong points are gobs of engine torque from 2500RPM to just below 10500
>redline, consistant neutral handling with little shaft effect, and a nice

>496cc 4 valves per cylinder (at least on mine, an 1982 CX500a)

What the hell's a CX500A?

>What I don't understand is that this engine has a nice,
>compact design with the cam right there next to the crank,
>and people say that it STILL has cam chain tensioner
>problems!

Not after 1978 1/2.  Unless 1983's automatic one has turned sour.

>A caveat about the E: the electronic advance on these things is (apparantly)
>notorious. When it goes out, what you are left with is the equivalent of a
>bike with a governor (my would NOT go over 52 mph) and it can be costly to
>repair (I got an estimate of $350). 

First I've heard it called unreliable.  As with any advancer, if it quits,
you're going to be way short on hi-rev power, hi-rev meaning anything over
about 3500 rpm :-) .  I don't know what the advancer coil costs, but it's
easy to replace.  Less likely is a bad steering diode in the CDI unit, but
if that's it, all you can do is replace the unit.  Spendy for the part,
but a snap to do.

>produced a respectable 50bhp.

>50bhp in its hot little pushrod dreams.  More like 30-35 at the wheel.
>Amazingly high redline (9500rpm) for a pushrod motor, but I suspect
>this was at the cost of valve lift and duration because the engine
>runs out of breath before then.  Shafty.
--
David Wise (DoD#427, davewi@orca.wv.tek.com, Packy -- 1980 CX500C)