[longdistancerider]

The manual transmission components will fit and work on the A model. As Bill mentions the timing will be 15* BTDC instead of 7* when started resulting in a higher idle speed.
Any of the manual trans 1978-86 CB/CM 400/450 models work including the CB450SC Nighthawk.
It will be interesting to find out if the A and manual trans pieces can work together.

 

[SHOBrad]

OK, you guys gotta allow me to rant on this for a sec. No disrespect to anyone that knows more about this than me (which is prolly most everyone)... My weed-eater runs, my edger runs, my JD rider runs. Back-pack blower, push mower, tiller... all run. These are all single cyl motors but essentially aren't the honda parallel twins the same since both plugs operate together? Maybe a little more throttle specific advance but really there is nothing new under the sun here so what is the magic-voodoo that is making these all so specific and special? If it's just the location of the pick-up can a 2nd key-way be broached onto the flywheel? Is there a retard/delay built into the CDI that is specific to each model based on the carb tuning/compression ratio/gas requirements.etc? Is this all about space requirements in the side of each engine? I feel in the dark on all this and stuck with a complete but non-running bike in my garage. Please let me know what I'm missing, any feedback would be greatly appreciated! Brad

Please know that I write this with the greatest respect and appreciation to all you guys that came before me and have been knee-deep in this too! Thank you.

 

[Bill H]

No big secret stuff here. When the motor is in neutral The change switch transistor is on . The motor will run with the side stand up or down. The motor will fire at 7.5 DBTDC thru the SCR 1 gate in the CDI unit and the SCR 2 gate is shorted thru the transistor. When the motor is in gear the change switch transistor is off and with side stand up the side stand switch is off. when the side stand is moved down the side stand switch is turned on and the CDI unit is grounded thru the SCR 1 gate stopping the motor. With the transistor off the motor will fire thru the SCR 2 gate at 15 DBTDC. All this is done between the change switch transistor and the CDI unit.Thats the main difference between the A and T CDI units.

Bill

 

[SHOBrad]

Thank you Bill, couple more questions... What does it say that my stater tests out good (in resistance range) per the Honda manual on alll except that the pink-to-green shows as open? Is this a problem and if so is it repairable?

what is the difference between the flywheel for the A and T? Only pickup location (timing) or is it pickup located farther/closer to motor?

Thank you again!
Brad

 

[Bill H]

My manual is in the shop and I have to leave in a little bit. Will get back to you tonight.

Bill

 

[longdistancerider]

The Pink-Green circuit is the advancer pulsar. Failure means there's no advance in timing.
The difference between your single engine units and the bike engine is that those units are working at a specific rpm constantly and the bike engine works thru a 9,000 rpm range. Load force is also in play here.
Can't answer the differences in rotor/stator components since I don't have any A model parts.

 

[ecm096201]

Not sure if this problem is solved, I am new to the forum, and have a 78 400 hondamatic that I changed the CDI on. As there were no CDI's available, I used one from the manual bike. The unit worked well at low speed but it clearly wasn't advancing. I soon realized that the advance pulser induction coils have completely different resistances on the different models. From what I understand, the automatic has a much lower resistance, somewhere in the neighborhood of 17ohms, while the manual is supposed to be around 135ohms. I haven't been able to get my bike to advance properly since replacing the CDI, despite rewinding the advance pulser coil. I am kinda shooting in the dark, as I do not know what AWG honda used or the exact number of winding on the coil.

This Forum is a Great wealth of knowledge, Thanks

 

[Bill H]

The A wont run right if at all with the T CDI unit ,I also tried it.It will run with the T stator and flywheel and CDI unit . You will lose all the safety features. Lower the RPM at idle to keep from shock loading the converter when shifting into gear. There is a sticky in the 400 elec section you should read.

Bill H

 

[Hondonnie]

I ended up returning the CDI from the 1980 CB, and ended up contacting Ignitech in the Czech Republic. After a brief discussion with one of their techs, I was able to arrange for them to send a programmable ICM, with the '78 CB400A program pre-installed. After about a week from initial contact, I received the new unit and this thing was absolutely well-produced. Extremely well-designed and using quality electrical components. After about 2.5 hours, soldering a few spare wires, rigging this thing up in the place of the original CDI; and boom! my '78 is back on the road again, running better than before honestly!

Only snag is I have a minor oil leak coming from behind the sprocket, but I'll have that fixed by tomorrow most likely (when the new seals come in)! All-in-all if you guys need to replace your CDI these guys are the way to go, trust me! Repairs only cost about $250.00 total (I also replaced the change relay).

Electronic for motorbikes - IgniTech P?elou? - all you gotta do is send them an email and they're super helpful, thanks again to the previous posters who dropped Ignitech's info back in 2011!

Just for clarification. The Ignitech module they sent you functioned with the 400a stator just fine? Did it have the two timing channels like the original cdi. Any more info would be much appreciated.

 

[Bill H]

You do know that thread is 2 years old. You might try contacting IgniTechP?elou? your self.

Bill H