There is odd
synchronicity that occurs in my life, at times. I acquired a mostly
original 1966 CA77 305cc Dream recently. I discovered that the
ignition point set was not the original, but one of the various
aftermarket copies, which are nearly impossible to adjust to OEM
specs.
Then, yesterday, I
wound up in a 30-message email exchange from a customer who was
rebuilding a CA77 engine and experiencing great difficulties with
the ignition timing. He sent photos of the engine’s cam timing
setup, which all looked normal. It’s kind of hard to get Dream cam
timing off a lot or even the point cam. The point cam is double-ended
for the 360-degree crankshaft Dream engines, so you can put it in
either way and it still works. If you do that with a 180 degree CB/CL
engine, you will wind up having to install the points plate upside
down in order to make the engine run.
My distant friend
(in Canada) was tearing his hair out because when the points were set
to normal gap, the ignition timing was about 30 degrees advanced. He
was concerned that something was wrong with the cam timing setup or
somehow installed the point cam in incorrectly. The point cam only
goes in one of two ways, so you can’t install it 30 degrees off, no
matter how hard you try.
My suspicions zeroed-in to the ignition points, which I have observed repeatedly as being
out of specifications in all cases if they are not OEM parts. I asked if the points were ND
stamped (Nippon Denso). I could see in the slightly blurry photo that
it was a ND point setup vs. the optional Kokusan designed parts. He
replied that the point plate said DENSO on it next to the contact
set, which didn’t tell me what I wanted to hear. I could see, even
in the photos, that the insulators for the point wire were a bright
red plastic, which is almost always a sign of aftermarket point
installations. ND uses a Bakelite-type of insulator which is a dull
red.
I sent him photos of
close-up images of new ND points and asked if they matched up with
what he had on the points plate. Another out-of-focus photo came back, taken about 3 feet away. Again, I asked: “Does it have the ND stamp
on the point contact set?” Finally, he replied that it didn’t
have ND on the points and he noticed a <F.E.W> mark where the
ND was supposed to be. I tracked down a couple of sources of genuine
ND points and sent links for him to purchase the correct parts.
<F.E.W.> aftermarket points. Note backing plate position
Somehow, he still
wondered if installing an electronic ignition would solve the
problem. Well, the answer is YES because the trigger wheel is held
onto the point cam with a set screw, so it has virtually infinite
adjust-ability. Eventually, he resigned himself to ordering a set of
ND points and will report back to me about the results.
Concurrently, I received prompt 4-day delivery of some Dream parts from DSS (www.davidilverspares.com), including a set of ND points and
condenser and set about to install them in the 3600-mile Dream
engine. As I extracted the old points, I looked at the contact base
with a magnifying glass and discovered <F.E.W> stamped on the
point set. The bike had been running with the points, but the point
backing plate was turned all the way to the right end of the
adjustment slot. The point gap looked to be about. .008”; just
enough to break the circuit but not what Honda specified normally,
which is .012-.016.”
Note that the rubbing block contact point is different between the two examples. ND at the bottom of the images.
With the new ND
point set installed, the end result was the backing plate set more
towards the center of the slot and the point gap around the.016”
range. The bike fired up normally and settled down after a brief
warm-up. What I did notice when checking the static ignition timing
is that if the timing was just to the right of the F mark on one
side, a full revolution put the point opening just between the T and
F marks! With a dynamic timing light, you will see the idle timing
marks shifting back and forth depending upon which end of the point
cam is being used. You can either leave it as-is and live with the
inaccuracy OR you can use a wet-stone to carefully work down the
point cam lobe that is more advanced, so that eventually both ends
are going to open the points right at the F mark alignment.
Nippon-Denso original points. Note backing plate position
In any case, DO NOT
ORDER/INSTALL any points that have <F.E.W> or a little three-blade propeller stamp which is from the Daiichi company. Both
aftermarket point sets will give you the same headache, without a
doubt. So, again, I say “No, no… a thousand times NO” to the
installation of any aftermarket ignition points that don’t have ND
stamped on them. The part number for the ND points is 259-004 vs.
259-003 for the Kokusan point sets, which will not install on a ND
point plate at all. There are aftermarket copies of the Kokusan
points as well, so BEWARE of fake copies. Unfortunately, for vendors
of those products, they are stuck with an inferior product that
should never be marketed in the first place.
And now you know....
Bill “MrHonda”
Silver
06-20
Wll said Mr. Silver.
ReplyDeleteI've read your post a few times. I bought some points on ebay that were said to be NOS for a 71 CL350. They are 333-004 with the ND stamp. They didn't come in the original Honda packaging that has me worried. Any other tips to validate authenticity?
ReplyDeleteGenuine ND points are stamped as such. All the copies have different symbols stamped on them. 333-004 points are for a CB350F, not a CL350 twin.
ReplyDeleteHow about Dixie Superior brand points? ;-). 4into1 actually sells decent points for the CB77. I currently have a set in mine now. They claim a stronger spring to prevent the points from floating at high RPM. I did not encounter any timing issues with their points.
ReplyDelete