Ignition Timing & Advancer

[Land_Shark]

Given everything I've read on the subject; it seems to me that a '79 motor w/ the revised (fixed) '80 469A advancer would provide the best performance (on a stock motor). Any thoughts

[RIPPER]

NO, the 79 has he proper cams and advancer,it's the 80 thats not right.

[Guest]

Ripper, I think you misunderstood me. The entire '79 motor w/cams and 422 advancer makes more power than the '80; but I've read that the 'revised' 469A advancer provides more degrees of ignition advance at certain rpms than either the original '80 469A or the '79 422 advancer. So it stands to reason that a complete '79 motor w/ an '80 'fixed' 469A advancer would benefit from further ignition timing advance.

[Land_Shark]

The above post was from me - stupid computer didn't log me in automatically

[sr71cbx]

Land Shark,
If you toss more advance at an air-cooled engine,it could suffer from metal mites(noticeable detonation).You are correct about the difference in igntion curves between the 422 and 469A advancers,however,the cam timing between the 79 and 80 models is what I think Ripper was emphasizing.The '80 model has .5mm(.020)less lift than the '79 cams on the exhaust and intake and the exhaust cam timing had been advanced 5 degrees to shut the exhaust valves @ TDC,effectively killing any overlap and thus the reason for the different ignition curve and more midrange power,also,emissions were a determining factor with the '80 models.Later model CBX's(81-82's)got the lift back on the exhaust & intake cams and retarded the exhausts 5 degrees.Intake cams on late models were advanced on the closing side 5 degrees to shut the intakes earlier and this along with exhaust system mods such as a crossover pipe and different header pipe lengths gave the late models more midrange punch also.
Hope this clears the air and doesn't open a can of worms....

[EMS]

During the 1980 model run a 469A dual stage centrifugal spark timing advancer was introduced and retrofitted by dealers to all engines SCOE3E-2000001-2001773, (frames in the range of SCOE-2000001-2001785) indicating that 1773 bikes had been built with the one-stage 469 advancer. Most of them were still in warehouses and in crates in November/December 1979 when the change happened. Reason was, that the 80 CBX with the single stage advancer fell about 5-6 horsepower short of its rated output. The dual stage advancer remedied that.
The 422 (1979) advancer is a two-stage unit also (God knows why Honda originally decided to change to a single stage for 1980) but the 469A advances the ignition a little sooner than the 422, mainly because it needs to match the different cams and carbs.
I would have to agree with Mark: the 469A in a 1979 bike will not be an improvement.

[Passx]

Just an FYI guy's. I have an 80 that I had bought and redid about 3 years ago and the S/N is #175 and contrary to the Honda published news briefs mine still had the 469 advancer in it and the big H was very happy to sell me the supossedly already installed correct 469a for $93. The original owner(s) had bought the bike new and drag raced it exclusively before blowing a hole in the #1 piston at 9500mi. After a rebuild and supposed blueprinting the original owner sold it to his partner/best friend who had always been the rider. Anyway he told me that the bike had went 11 o's @ 120 mph (no freakin way) and after a few more years and a Harley the "X" was put in a barn for 12 years. After I got it and freshen'd up the carb's and screwed the #1 float seat in so it'd get some gas (wonder why it holed a piston) I dyno'd it with it's antique Alphabet 6-2-1 header and was thoroughly amazed that it made 73 hp at the rear (typical stock 79's are 84-86 I believe). The installation of an 469a on my bike brought the HP up to 76hp with a lot more tuning and getting the Dynojet kit leaned out it now make 92hp. Anyway that's my story, where's the beer ?

Steve P. #5220

[EMS]

Steve:

Really not surprising. The 469A advancer is NOT supposed to be in early 1980 bikes. When the change was made, approx 1,700 bikes had left the factory already. Dealers were supposed to replace the advancers in all bikes they had in stock. If one made it out to an end customer already, it was supposed to be changed as a special service. Very possible, your bike was never returned to the dealer for the change.