1982 Honda CB 900f low charge

VintageMBike said:
i put the system in. At Idle im at 12.4 12.5. At 4k rpm im at 13.5 and up

Is this acceptable? Also, if I put the headlight off (i detached it) things run a lot better. Not sure what kind the bulb exactly is, but its says H4 on it.
Click to expand...

Sounds about right.

At idle it sound like you're running off the battery. Ideally you want to be seeing about 13V before you can consider the system to be self-sustaining, but that's not super-common on permanent magnet alternators for vintage bikes.

H4 halogen bulb can have a very wide range of wattages, so just being H4 doesn't tell us a lot. If you plan to be idling a lot, a swap to LED lighting might help.
 
Sonreir said:
Sounds about right.

At idle it sound like you're running off the battery. Ideally you want to be seeing about 13V before you can consider the system to be self-sustaining, but that's not super-common on permanent magnet alternators for vintage bikes.

H4 halogen bulb can have a very wide range of wattages, so just being H4 doesn't tell us a lot. If you plan to be idling a lot, a swap to LED lighting might help.
Click to expand...

So, 10 days in the new rectifier s fried but the stator and rotor are fine. What could be cause this rectifier (podtronics) to fail? I know the bike gets hot, but this is ridiculous.
 
at 4k rpm you should be getting 14.5 with a good battery

so something is off

all my dohcs get 14-14.5 at 4 k
 
Not all regulators produce the same voltage. Where did you install the reg/rec? They produce heat on their own, so if it's in a hot location where it can't cool and then it's taking in heat that could cause a failure. Is the resin on the back blistered?
 
honda wants 14.4 at around 3-4 k

here is a good dohc write up

http://www.cb750c.com/publicdocs/charging_system/genesound_charging_system.html
 
cxman said:
honda wants 14.4 at around 3-4 k

here is a good dohc write up

http://www.cb750c.com/publicdocs/charging_system/genesound_charging_system.html
Click to expand...

There is a draw somewhere within the harness. The new Cycle X charging system is OUTSIDE THE harness. It doesnt link up to the harness AT ALL! It goes direct to the battery.

Perhaps there is a draw somewhere within the harness.
 
VintageMBike said:
There is a draw somewhere within the harness. The new Cycle X charging system is OUTSIDE THE harness. It doesnt link up to the harness AT ALL! It goes direct to the battery.

Perhaps there is a draw somewhere within the harness.
Click to expand...

Almost everything in the harness is a draw. :p

But the charging system does link up with the harness at the battery, so the two systems are not strictly separate.
 
Sonreir said:
Almost everything in the harness is a draw. :p

But the charging system does link up with the harness at the battery, so the two systems are not strictly separate.
Click to expand...

Thanks for responding. I talked to an older guy in the forum and he insists, no matter what I do, if the bike is stuck in traffic and not "breaking even" while charging, that the battery problem will not go away. The revs have to stay up. The bike only charges at 3k rpm + revs. Sound about right to you?
 
Sort of... but that's only part of the story.

It's like two sides of a traditional set of scales:
512px-Johnny-automatic-scales-of-justice.svg.png


On one side you have power generation from the charging system and on the other side you have power consumption (all the electricity your bike uses).

You have some control over items on both sides. If you're not able to increase power creation, you might want to take a look at power savings. LED light bulbs are a good option (especially for the headlight). Using 5 Ohm ignition coils (stock) instead of 3 Ohm coils (many aftermarket brands) is also a good power saver.
 
Sonreir said:
Sort of... but that's only part of the story.

It's like two sides of a traditional set of scales:
512px-Johnny-automatic-scales-of-justice.svg.png


On one side you have power generation from the charging system and on the other side you have power consumption (all the electricity your bike uses).

You have some control over items on both sides. If you're not able to increase power creation, you might want to take a look at power savings. LED light bulbs are a good option (especially for the headlight). Using 5 Ohm ignition coils (stock) instead of 3 Ohm coils (many aftermarket brands) is also a good power saver.
Click to expand...

Great explanation. Therefore, I also might want to check "the other side" - that is, the power consumption side, to see if anything is grounding or shorting, which would interfere with the power generation. Sound right?

Also, when I attached the regulator/rectifier directly to the battery, i didnt tighten the negative side crew. Could that have resulted in the recent demise of my 10 day old rectifier? Which resulted in a depleted battery?
 
Most grounds or shorts are severe enough that it will cause fuses to blow. It's not impossible that this is a problem, but it is unlikely.

And yes, a loose battery connection can definitely fry electronics. It causes something called "load dump". https://en.wikipedia.org/wiki/Load_dump
 
Sonreir said:
Most grounds or shorts are severe enough that it will cause fuses to blow. It's not impossible that this is a problem, but it is unlikely.

And yes, a loose battery connection can definitely fry electronics. It causes something called "load dump". https://en.wikipedia.org/wiki/Load_dump
Click to expand...
Load dump is a complete disconnection. A loose connection cause a higher resistance and overheating of circuits. I know you know that, but your answer seemed misleading or at least open to misinterpretation.
 
Depends on how loose the connection is. Interruption of even a few milliseconds can cause load dump. Loose, but not fully disconnected, terminals will definitely cause the symptoms you're describing.
 
on that cyclex system make SURE the regulator has a clean bare metal ground when its bolted down or they dont charge right
 
cxman said:
on that cyclex system make SURE the regulator has a clean bare metal ground when its bolted down or they dont charge right
Click to expand...

The regulator that comes with the Cycle X unit is ground via the battery. + and - go straight to the battery.

Mine got fried because the negative connection to the battery was loose.
 
we did one on a sporster and it would not charge right til we grounded the reg as well

maybe they have modded it
 
cxman said:
we did one on a sporster and it would not charge right til we grounded the reg as well

maybe they have modded it
Click to expand...

Mine was charging properly with no problems.. It failed because of a loose connection to the battery.
 
You must log in or register to reply here.

DTT Light or Dark

  • DTT Light
    • www.jadusmotorcycleparts.com
    www.lostapostle.ca/
    www.sparckmoto.com

    Spread the Love

    Back
    Top Bottom