CB100 K1 Electrical issues

[Mistermint]

I am currently having electrical issues with my CB100 K1; some of which are on going and some new!! I will list.

1) When the brakes are applied the indicators (winkers) virtually stop working.

2) The bike runs but after around five minutes just stops with a complete loss of electric power. leave the bike for a few minutes and the electrics are ok again.

Since being imported from the USA I have:

(a) fitted a new wiring loom
(b) cleaned all connections
(c) replaced the Selenium rectifier with a solid state on
(d) fitted the correct battery

Any ideas as to the root cause of the fault(s)s and possible solutions.

Richard   

[McCabe-Thiele (Ted)]

Sounds like a bad earth connection.

[Bryanj]

Sounds like its not charging properly to me, common for indicators to go slow with brake light on

[Lobo]

Put a multimeter (on a 10A scale) in series (ie between) the battery +ve post and it’s lead. With engine off, you should see -ve amps with electrics on (eg brake light), and with engine running a charge (+ amps).

Multimeters can be cheaply found eBay etc, be sure to get one with a 10A scale.

You’ll have a better idea of how to proceed once known, and said multimeter can be further used to troubleshoot wire continuities etc.

I assume the bike has a magneto? Just sold a Fizzy with magneto / 6v system… you almost had to choose between head, brake… indicators as having all on together was a big ask 😂.

[Laverda Dave]

Does the CB100 use a 6v electrical system? Is the new rectifier of the correct voltage and type, i.e. a direct replacement of the selenium rectifier and did you buy it from a reputable supplier, there are a lot of 'universal' types on ebay? The indicators would struggle to operate if there are any bad earths anywhere on the bike. Check the charging circuit as advised and double check the earth points are really clean.