Is my CDI box junk??

In my other thread I said my cali bike was much slower than my 49 stater...it was and it is

I have been investigating for days and have noticed that the bike is intermittantly dropping its front left cyl.

History: the bike is stock, appears to have been well cared for and not tampered with...but it was dropped and roadrashed a bit 3 years ago. It sat ever since. I got the carbs clean and working again, went through the normal stuff. The tank is clean, the fuel system is fine. All four cyl. seem to have equal compression. The front left plug seems to fire OK when I pull it out and check it

Here is the thing that makes me think the CDI is at fault: the regulator was fried to the point that metallic bits had melted their way through the rubber housing...it makes me wonder if someone has used a jumper box intended for automotive systems on the bike and surged the system badly, possibly damaging the CDI.

has anyone ever heard of a bad CDI box that seems to work OK at times but loses spark to one cyl?

I have substituted a known good ignition coil onto the bike to no avail. So I feel I have ruled out poor compression, fuel system problems, ignition coil problems, plug cap and wire problems, and I doubt that the pulse generator is at fault since all 3 other cyl. seem to run fine (pipes hot at start up, where the front left is cold, warms up slowly, then goes completely dead)


help!! my california bike needs help...or maybe I need help since I am ready to shoot this bike

 

Cdi

I would say you are way off with the cdi.Pull the plug wire and stick another spark plug wire in it and see if is sparking while it is running.I fit does stop firing let me know and we will trouble shoot from there.Or if you have or can get a Fluke 87 you can just test in frequency mode to ckeck firing.

 

I have tested with known good coils and plug wire/cap combo's. all of the above, both the original and the known good units spark fine with the plug out of the bike. Upon putting the plug back in, the bike will run a spotty on that particular cyl. and finally drop it all together. It will foul the plug if I persist in riding it. I have just checked compression and the cyl. has just about what the others have. The only other thing I can come up with is a stuck choke needle, but it appears to function normally. There is raw fuel leaking around the header area now. i have just verified that the float is in that carb is working nowmally...it seems there is not much left but a long shot like the CDI

 

if raw fuel is leaking and plug fouls the float needle is NOT working properly or set way wrong........

If plug turns black when that cyl stops working=excess fuel.

Bad cdi won't fire plug in or out of cyl.

Try old 2-stroke riders trick: with engine hot, switch plug from good-running cyl with non-runner and try again.

 

Thanks to the guys who insisted I look closer at my carbs. I am cautiously optimistic...i found that a tiny backflow valve next to the air jets in the carb mouth was not flowing on the particular carb in question. I think this little deal is ther to equalize pressure or allow excess vacuum to bleed off.I believe this was causing the bike to suck a crazy amount of fuel when the throttle was closed and the bike was coasting. I need to get some more CR9EH plugs from the honda dealer tomorrow since I am working with fouled junk at the moment, but the bad cyl. seems to be firing, the pipe is hot, and the bike sounds normal.

 

your theory is questionable, but maybe the new plug will help......

 

The proof is in the pudding, although I do not fully understand the function of these air "jets", the bike is now running very well. It was a night and day difference.