Topic: Another No spark/low voltage?

[MotoBro]

1974 CB550

-Top end rebuilt
- Coils tested and are within tolerances
- Spark plug boots are crap (reading almost 8 ohms, supposed to be 5 )
-By passed Kill switch wire ( Black and white into black)
-By passed Clutch switch ( Green and red into green)
- New and clean points properly gapped
- Using a Battery Jumper pack with the alligator clips (reading about 13volts
- Black and white Wire going to the coils is reading 11.6 volts (Is something draining it?)
- Headlamp is unplugged
- Starter motor is dead (apparently- Crossed the starter solonoid, got a big fat spark and got nothing)
-Get nothing if I press the starter switch (although the neutral does dim and the voltage at the coil junction goes to 10)
- When I kick it goes up to 11.7 volts and back down Oil pressure light comes on
-Bike is in Neutral


So thats the starting point basically.  Looked at most of the other threads on this before posting and am using this diagram for wiring.

http://oldmanhonda.com/MC/WiringDiagrams/CB550.jpg

*additional note, The Horn I believe is shorted out at the actual horn (wires are fine)

I have new boots coming but I think its more important as to why I'm only getting 11.6 volts at the black and white junction into the coils. I dont have the headlight on so I have no idea what could be possibly draining the system

[Deltarider]

- Spark plug boots are crap (reading almost 8 ohms, supposed to be 5 )

Are you talking Ω or KΩ?  8KΩ is perfect. 5KΩ is fine too. If you read 8Ω, it would mean it's a resistorless plugcap. They exist, but I doubt you have them on your bike.

- Using a Battery Jumper pack with the alligator clips (reading about 13volts

I don't know much about jumper packs but you could use a known good battery. My neighbour has a jumper pack that's a piece of junk and he'd better have saved the money for a battery.

- Black and white Wire going to the coils is reading 11.6 volts (Is something draining it?)

Not necessarily. With the ignition on, current goes through a coil (at least one) to ground which is like a lamp burning and for a 12V battery system to sink to 11,6 Volts is not abnormal. There is still plenty of juice for the ignition to ignite. You haven't informed us if your plugs spark or not.

- Starter motor is dead (apparently- Crossed the starter solonoid, got a big fat spark and got nothing)
-Get nothing if I press the starter switch (although the neutral does dim and the voltage at the coil junction goes to 10)

Again, I dunno what your jumper pack is capable of, but I'd use a known good battery.

but I think its more important as to why I'm only getting 11.6 volts at the black and white junction into the coils.

Again that's not abnormal. At least one coil is consuming power (and so drains) and voltage will sink somewhat. If you switch the ignition off you can easily check for drainage by using an ammeter. Disconnect either the + or the minus cable from the battery, connect the ammeter in between and see if there's any reading. Do not use starter unless you wanna see the testwires melt!
If bike has stood for a long time like in hibernation, I recommend switching the ignition key a dozen of times and the kill switch idem dito, just to clean the contacts inside somewhat. I do that every spring before I connect the battery.

[BomberMann650]

+1 what delta said about the battery.

[Bodi]

First, those boost things are crap. They can recharge a (good but discharged) real battery enough to start a motor. There is NO WAY the 16450 lithium cells will provide starting current - that is just impossible, max for high current cells (expensive and not the type in those crap boost packs) is around 20 amps.
So the starter motor not turning means SFA until you get an actual battery.
The solenoid might be stuck, it happens. The Honda ones are rebuildable exept the coil assembly is sealed but that is rarely the problem.
The voltage drop would be a problem but did you measure drop or voltage at the coil only? Is the battery voltage dropping or is it a loss in the harness? 11.5V is plenty for good spark regardless.
You should have 5k or 10k plug caps. Sounds mental but the resistance makes the sparks better. Zero Ohm caps are ok with resistor plugs.
All the weird symptoms could just be a weak power source. The starter button is connecting to something which might be the solenoid. Do you have a starter safety unit or a diode to isolate the neytral light from the clutch switch? The ssu can cause oddball problems while the diode is pretty stupid and either works or not - the neutral light comes on with the clutch switch ot it won't chooch in neutral.
Jumper to a car. There are BS scare stories that this is dangerous but all untrue. Just (IMPORTANT!!!) have "-" black negative jumper cable to frame and "+" positive red jumper to the red battery wire. Reverse that and expensive trouble.

[calj737]

11.6v at the coil on BLK/WHT with the headlight unplugged is more likely resistance than draw. check the fuse block, both sides. Clean all the contacts (especially the backside. Make sure the battery ground wire to frame/motor is touching clean bare metal. Check the resistance of the BLK and the BLK/WHT wires. Your stock key switch and stock KILL switch are likely to have accumulated too much corrosion and thus reducing the voltage at the coils.

As for the starter motor, it grounds to the cases. So that connection needs to be clean too. You can test independently by running power to it directly and bypassing the solenoid. Shorting/jumping the solenoid is not conclusive that the issue is the starter and not the solenoid. With power to the solenoid, it should "click" if properly grounded. Since you bypassed the GRN/RED wires.y may have inadvertently severed its ground while doing so.

Hope some of that helps-