Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: Coppertop1234 on July 23, 2026, 01:04:39 PM
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Hi all bit stuck with diagnoses of slight problem.
Bike on trickle all time in garage.
Starts on the button no issues
Go for a run 20 40 miles perfect ride.
Go to use button to stat and starter tries once and stops
It's like a flat battery symptom
Bike kick starts first kick ride home same issue.
Mega shows Bike is charging
New battery
Earth's all cleaned
New wiring loom
Changed stator just in case
New switch gears
Last thing I can think is regulator rectifier
Open to views if anyone has had similar?
Cheers
Keith
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Bit of a,long shot, if you're on oem regulator, check the wire wound resistor on the back of the regulator.
I had a battery go off last season and checked all the obvious bits that you have. Cleaned the regulator contacts and left a fragment of of paper towel between the normally closed contacts, wasn't charging at low revs and a spanner wouldn't stick to the alternator cover with ignition on.
It was fine on open roads but draining the battery pottering around town.
Since fitted a voltmeter. You need 3-4000 revs to get any meaningfull charging. Once you're up to speed or over 6000 rpm it should be up to 15v and not go over.
If you are running aftermarket ignition coils with a lower resistance and headlight on it might struggle a bit unless you ride it like you stole it.
Regards
Dave
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Regulator and Rectifier are seperate parts unless the bike has been fitted with an aftermarket unit
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All standard fit at moment but I am down to these as my last options.
Aftermarket do a multi 2 in 1 version to do both jobs
They are.not too dear but didn't want to change if I was missing something simple someone else had already diagnosed.
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Have you checked the contacts inside of the generators multi connector, they are known to corrode badly and the vibration as the engines running could mean they lose contact and don’t allow the battery to charge.
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checked connectors all seem fine
Battery on trickle all week reading 13.48
tried electric start twice getting fuel through
no 3rd attempt flat
Kickstart first attempt (all be it me standing on 2 bricks so i could kick it up)
mega reading 14.28 14.5 at battery while revving bike
so battery holding charge ok and bike charging ok
a lot of drain for just 2 attempts with electric start.
think i will try taking starter out and cleaning it up or if i have a spare replace it just to rule it out.
puzzler??
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Trying to think outside the box, following are my thoughts
1. Is the solenoid faulty?
If you bridge the contacts when the battery is apparently flat does it crank over.
2. A new battery, is it definitely the right specification?
C.C.A. and Ah rating, voltage alone does not tell the whole story, new batteries can be mis-labelled apparently.
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Load test the battery because it seems like a faulty cell breaking down under load.
Or try another battery first if you've not got a tester.
Good luck
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like the thoughts guys
will check them out tomorrow
Ta
Keith
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Main cable from battery to relay/starter OK/connections good?
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Definitely sounds like a duff battery, irrespective of its age. It may have been a bit older, but I have just had the same problem with my 250. (No kickstart!!!). Left it on charge overnight, was reading 13.8 volts, touched the starter button in the morning to check. Magic!!. Went indoors to put all the riding clobber on, pushed bike out of garage, pressed starter button and all it did was kill the neutral light. New gel battery fitted, sanity returned.
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All sorted it was the brushes in the starter motor.
Replaced with a spare and starts so much quicker ,motor hardly spins and she's away.
Thank you for comments during diagnoses process.
Cheers
Keith
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Interesting
I had similar issues with the dyno/starter on my Yamaha CS5
turned out to be carbon dust between the segments on the cummutator ring,
Narrow screwdriver cleaned the gaps,
Now working properly
The little things
I had no previous experience with these, but live and learn
Sent from my SM-A546E using Tapatalk
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Thanks for posting the conclusion to the problems.
Always learning stuff on this forum.
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Now you have identified the problem, were there any other signs you might have missed, such as a hot starter casing, that made you look at the starter itself?
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No not other signs Ted just started with full battery 1 or 2 times then nothing on button.
With it staring i never thought it would.be the actual starter,but then again sometimes you miss the obvious when you are rebuilding and question everything but.