Advice: debug Honda 8HP charging system

isaksp00

Petty Officer 1st Class
Joined
Jul 14, 2010
Messages
225
My BF8A (manual start) has poor (like 0.1V) voltage from the charging plug. I checked the V at the wires before the fuse, same result. This was after having tried to charge a more or less discharged battery. Cable to battery was disconnected while I tested the V.

I have a shop manual, and will test the resistance to the various rectifier leads, once I haul the boat in a few weeks.

Seems like there are only 2 real components to the charging system - the charging coil and the regulator/rectifier. Barring a wire problem, I assume failure is from one of these two devices. The coil looks to be pretty passive, so I am guessing the rectifier is fried, and have read that disconnecting the charging plug while engine is running can easily do so - prev owner may have.

I have also read posts (other motor brands) where people have measured what looked like some AC voltage out of the coil, assumed a bad rectifier, replaced it, and still no output.

Any advice would be appreciated, if anyone has:
- Determined a way to test quality of coil output, given I only have a simple meter, with std functions like DC V, AC V, ohms, and also DC amps. Is there any other device that'd help me assess, short of an expensive oscilloscope?
- Figured out if some substitute rectifier can be used, even temporarily, connected to outputs of coil, to verify that coil is OK (that is, it is worthwhile to buy a rectifier). Better yet, since a Honda rectifier is around $125, are there compatible devices from other sources? Seems like I could route the AC output from the coil via the charging cable that is in place (or maybe I need a different wire type) to a rectifier/regulator mounted in lazarette, near battery.

Basically, what techniques can be used to figure out what to fix?

Thanks.
 

hondon

Lieutenant Commander
Joined
Jun 11, 2001
Messages
1,922
Re: Advice: debug Honda 8HP charging system

If the oil light is on while you are running your charging system is working.This unit needs to see a load at that charging port to work and that means it needs to be connected to a battery.You ca'nt run lights,electronics,etc,etc,from that charge port.That pathetic 6 amps that charging system offers is a little hard to measure.
 
Top