Not Sparking

[Buckrabbit]

Hi, folks,
The story so far, My wife (bless her) bought me a CB1 for my birthday,
it ran fine, slight leak on carbs, fixed the carbs and parked her up, last week uncovered her (the bike not the wife)
new fuel, freshly charged battery, lots of turning over then signs of life, very hesitent it sounded if it was only running on three well two really but i know it cant, then very loud backfire through exhaust, after peeling our pet cat off the garage roof and mopping up spilt coffee i set about trying to find the problem,
checked carbs, fuel pump, everything ok with them, next tank off plugs out (my mate says they can break down if the bike is stood for a while) couldnt really belive new iridium plugs would fail after 50 miles and 9 months dry storage but hey ho    
So new battery fitted, no sparks, new plugs, still no sparks, checked all fault finding in service manual, it indicated bad spark pack, changed spark pack still no sparks,
re checked all switches, engine run switch, fuses etc, still no spark, battery showing over 11.5 volts whilst turning over
whilst on my knees at the side of her offering up a small prayer to the great mechanic in the sky i noticed the Reg/Rectifier looked a little cooked, opened it up looks more cooked, tried to test it as per service manual no readings at all, i dont know if this is due to my meter or not (the manual specifies a certain type/make of meter for these tests)
anyway ordered new rec/regulater, but i thought this was only for the charging side of things, could it stop it sparking?
anything i am missing here?
Regards one very pi**ed off born again biker.


    
    

[MitchZ]

It looks like you are doing all the troubleshooting steps. I am new to the CB-1 too, purchasing my 1990 -1 on 10/31/11. One thing I did notice in perusing the posts here and elsewhere is that the -1 is quite sensitive to having a weak battery. One of the problems are cooked electronics. My 1975 Norton destroyed my sprag gear (part of the electric start) due to a weak battery which was a $700 (US) repair.

My feeling is that once you replace the rectifier, your problem will be rectified.

Anyway, welcome to the site (great, helpful people here), enjoy your -1 (great, fun bike), and I envy you for having a wife who buys such a wonderful gift!

[rigwit]

If you suspect the reg/rectifier is U/S and can't get any meter values it is because the rec is mainly Diodes------ so check the stator coils to check all are ok values in Ohms....

3 yellow wires should  5 ohm to any yellow/yellow............ for cdi unit.. ignition on-engine run switch- on cdi unit power input Black/whitetracer, and ground should be battery voltage. .Pulse generator-yellow wire and white with yellow tracer 340 -420 ohm.  Ignition primary coil 1-4-black with white tracer and yellow with blue tracer- 2 -4 ohm,       primary 2-3 black with white tracer and blue with a yellow tracer 2 -4 ohm.

[Buckrabbit]

Test results,
black and white - ground = battery voltage
pulse generator 395 ohms
primary coils 3.6 ohms
secondary coils 13.66 ohms
alternator charging coil 1 ohms between any yellow - yellow give or take 0.1 ohm, no continuity to earth on any
test results in service manual are observed at 20 degrees temp
test results above are at 4 degrees temp with reg/rectifier removed

[rigwit]

alternator charging coil 1 ohms between any yellow - yellow     looks like stator coils are U/S........ or you have what is termed,(black wire) syndrome. with a u/s reg/rect' then if stator coils faulty would kill it and battery to...

[Buckrabbit]

I have just tested multimeter leads, touching them together reads 1 ohm
so subtracting that from the 1.1 ohm reading (which i should have done in the first place) i seem to be in range
using 1 ohm subtraction in every test result keeps me prety much in range very slightly under on secondary coil

Not sure if this applies to my bike but my mate says his kawasaki KLF350b cdi unit recieves an initial voltage pulse from the pulse generator  then the spark unit obtains stable voltage from the battery and regulator to send full voltage pulse to the coil
so on his bike the pulse generator triggers the CDI but the power for the CDI comes from the rectifier
is it the same with Honda?
 
if you think the dog looks miserable you should see me.

[Buckrabbit]

Latest news,
 fitted new Reg/Rec still no spark,
now i am thinking if one coil is breaking down but not enough to show being broken down completely  it may be bringing voltage down enough to prevent other coil energising so no spark, and also effecting tachograph (that doesn't even twitch on turn over)
any thoughts folks?

[dasch]

Buckrabbit, if shorted multimeter probes on ohm reading give you 1 ohm, and reading of yellow to yellow give you 1 ohm that means your aternator coils are shorted. Burned. F'd up. Subtract 1 from 1 you get zero! Short circuit. Or am I reading this wrong?  You should have few ohms between all three yellows, say 5-6 at least. Regardless, it should not affect the starting, which seems to be your initial problem. You know what I do in these cases? I jump from a car. That gives you bigger and better supply of amps. I actually jump from an idling car, but that may start a firestorm on forum. 

[91cb-1]

That's a gorgeous bike mate, not so gorgeous dog, both look like they're a lot of fun though

[Buckrabbit]

Running at last,
Changed entire wiring loom, lights brighter, horn sounded crisper, and fired up first go
must be a short in the old loom somewhere

[guntherrex]

glad you got it sorted. I'm on a similar project right now