CB400SF Reg/Rec problem?

[danny_g]

Hi all, new to the site (and bike riding for that matter).

Have a 1992 Honda SF400, good little learners bike. I've just replaced the battery, as in it has about 100km's on it. Went to go for a ride this morning and it wouldn't start. Had warning lights, horn, headlight etc ok, although when I tried to crank it over the headlight dimmed. Not a murmur from the starter motor. Connections ok, fuses all good. Bump started it ok, got about 1k down the road and it just died. All the warning lights and headlight were much dimmer.
I had the same problem with the old battery, just died and wouldn't start. Unfortunatly that was about 70km's out of town.
To my mind the battery isn't being charged, although thought that if it was crashed started ok then it would run ok, even with a flat battery. Noob mistake?
Anyway, a mate of mine thinks it may be a bad regulator/rectifier. Any ideas?

[gammaguy]

Hi all, new to the site (and bike riding for that matter).

Have a 1992 Honda SF400, good little learners bike. I've just replaced the battery, as in it has about 100km's on it. Went to go for a ride this morning and it wouldn't start. Had warning lights, horn, headlight etc ok, although when I tried to crank it over the headlight dimmed. Not a murmur from the starter motor. Connections ok, fuses all good. Bump started it ok, got about 1k down the road and it just died. All the warning lights and headlight were much dimmer.
I had the same problem with the old battery, just died and wouldn't start. Unfortunatly that was about 70km's out of town.
To my mind the battery isn't being charged, although thought that if it was crashed started ok then it would run ok, even with a flat battery. Noob mistake?
Anyway, a mate of mine thinks it may be a bad regulator/rectifier. Any ideas?

Charge battery

Start engine

Check charge rate with multimeter...should be around 13v across the battery,check your manual for exact specs.

If no charge,suspect battery first,if that's OK suspect regulator rectifier,if they are all OK its your charge coils in the alternator,or possibly all three of the above

Good luck

[spanner spinner]

Charge battery

Start engine

Check charge rate with multimeter...should be around 13v across the battery,check your manual for exact specs.

If no charge,suspect battery first,if that's OK suspect regulator rectifier,if they are all OK its your charge coils in the alternator,or possibly all three of the above

Good luck

yep do what gammaguy said, when you test the charge coils test for connection to the engine cases there should be none and check there out put, they should show more than 20 volts at idle building up to 60 to 70 volts at 5000rpm. these voltages need to be tested at the three pin connection between the coils in the engine and the reg/rec.If you don't have the gear to do the tests pm me as I do this sort of work every day and can have a look at it for you.

[hayd3n]

yep do what gammaguy said, when you test the charge coils test for connection to the engine cases there should be none and check there out put, they should show more than 20 volts at idle building up to 60 to 70 volts at 5000rpm. these voltages need to be tested at the three pin connection between the coils in the engine and the reg/rec.If you don't have the gear to do the tests pm me as I do this sort of work every day and can have a look at it for you.

friend has similar problem on her speed 4 shes on her 3rd reg rect stator :( and a brand new battery

[danny_g]

Thanks guys, will check it out.