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General Category => Tech Corner => Topic started by: titsonfish on September 22, 2017, 05:00:13 PM



Title: Trouble starting - Power loss - Cut off
Post by: titsonfish on September 22, 2017, 05:00:13 PM
The bike has done me well for a while and one day it struggled to start with the electric, but fired anyway after a moment, on the trip home it refused to start and so i bumped it off, rode home fine.

When i got home i turned it off and fired it up again multiple times without issue.

The next day it refused to start, and sounded like the battery was dying, except the battery clearly wasn't dying. Bumped off okay and got me to work, however 100 meters from work i experienced engine stutters and as i sat idle it turned off.

Hours after work it bumped off okay and got me home, then i changed all the spark plugs, checked the air filter too and the carbs.

After this the bike fired up with the electric no problem multiple times.

Twenty minutes later it wouldn't start and had to be bumped off. Took it for a twenty minute round trip and it ran fine, even electric started multiple times when i got back.

Took the bike out for a 12 mile shunt as a proper test ride and it started electric, but didn't seem to want to. Ran the 12 miles no problems at all.

Stopped for 10 minutes and then it refused to start, sounded like the battery was losing all power. Tried to bump start it and it refused. Wouldn't even pretend like it was going to start. No noise at all, all electrics were otherwise working perfectly.

Fifteen minutes later the bike bumped off and i left it running idle for 25 minutes without issue, then set off and it cut off 10 meters up the road, but then bumped off and seemed to run fine for several miles.

Bike then started to lose power as i was riding until it cut off and left me with several miles of walking to do with a bike.

After this it refused to start. Electric sounds like a buzzing and bumping it produces no results at all, not even pretending to try.

I would appreciate any help you can throw my way (New battery arriving tomorrow)


Title: Re: Trouble starting - Power loss - Cut off
Post by: a_morti on September 23, 2017, 05:48:47 AM
Sounds electrical for sure. Batteries can drop a cell, you'll see enough volts to light a headlight, but put on something with more drain and it'll give up. More likely the battery, but also might be worth opening the starter for a clean and inspect, if the brushes were very worn it may have trouble starting, the brushes are renewable so not a big deal.

Wouldn't hurt to get a multimeter on it and go through  the usual voltage checks.

Let us know how you get on.


Title: Re: Trouble starting - Power loss - Cut off
Post by: filterMan on September 23, 2017, 09:34:17 AM
If it's cranking slowly when you press the starter switch it's worth having a go at jump starting it from another known working battery. If it spins into life it's probably the battery. If it still cranks slowly it could be a bad earth or as a_mort says, the starter motor brushes.

That said, the fact that your bike has died a couple of times suggests some other electrical gremlin. After the bike has died, when you press the starter switch, is it cranking slowly?


Title: Re: Trouble starting - Power loss - Cut off
Post by: titsonfish on September 23, 2017, 09:45:02 AM
I'll keep you informed as to what happens, but at the moment i am waiting for the battery to arrive and if it isn't that i'll take a look at the starter motor. I just really hope it isn't the ignition coils.

To answer your question though, no it doesn't slow down, it sounds very much like the battery is dead, which is a bit odd and makes me think it may have something to do with the reg rectifier.


Title: Re: Trouble starting - Power loss - Cut off
Post by: a_morti on September 23, 2017, 02:33:51 PM
Once it's started, check for any cold exhaust downpipes. Could just need he HT lead shortening for a better connection .


Title: Re: Trouble starting - Power loss - Cut off
Post by: titsonfish on September 25, 2017, 11:58:46 AM
Okay, as an update - The bike refused to start and simply made buzzing noises prior to me ordering the battery, now i have installed the new one it is doing the same. Bike won't start and just buzzes.

Unless you guys know better i'm going to have to replace the ignition coils next and look at the starter motor as previously advised.


Title: Re: Trouble starting - Power loss - Cut off
Post by: a_morti on September 25, 2017, 12:56:48 PM
Could you put up a video? I can't picture what buzzing you mean. It sounds like could be any of starter or starting clutch or solenoid.
There is a Facebook group if that's easier for you to upload.
https://www.facebook.com/groups/1119747858086718/


Title: Re: Trouble starting - Power loss - Cut off
Post by: titsonfish on September 25, 2017, 02:15:57 PM
Exactly this

https://www.youtube.com/watch?v=VgigG6j_hb8&ab_channel=JohnNelson


Title: Re: Trouble starting - Power loss - Cut off
Post by: a_morti on September 25, 2017, 02:53:38 PM
The noise that bike is making is the starter solenoid. I'm fairly sure of it. The cb-1 keeps its solenoid under the right hand middle aluminium panel. Take that off and see if it is that.

If it is, and you are sure your new battery isn't at fault, then it could be the solenoid itself or some bad connection along the line, perhaps a loose or corroded cable on the solenoid or starter.


Title: Re: Trouble starting - Power loss - Cut off
Post by: titsonfish on September 25, 2017, 05:29:32 PM
Awesome, you're awesome, i appreciate the help.

That's my next job then.

Solenoid is ordered, hopefully it will arrive tomorrow and i'll have a go with putting it in.


Title: Re: Trouble starting - Power loss - Cut off
Post by: a_morti on September 25, 2017, 06:19:29 PM
First thing would be make sure I am right, it will only involve removing the RHS side cover. Next thing, check the plug on the solenoid which often gets water ingress, if yes then clean up corrosion and try again. Only then would I buy new parts.


Title: Re: Trouble starting - Power loss - Cut off
Post by: titsonfish on September 28, 2017, 04:04:35 PM
Just to keep you updated - Replacing the solenoid worked like a charm. Thank you for the help.


Title: Re: Trouble starting - Power loss - Cut off
Post by: titsonfish on September 29, 2017, 02:40:11 PM
Okay, so the coolest thing happened.

The bike has been working fine since putting the battery and solenoid in, and today it reached the 12 miles mark and cut off, refused to even pretend to start and wouldn't bump either. Left me with another fucking big ass walk home  ;D

Okay. My best guess is coils or regulator rectifier, any help would really be appreciated.

To be clear, it's having exactly the same issues as last time.

In the mean time i will be looking at the starter motor brushes.


Title: Re: Trouble starting - Power loss - Cut off
Post by: Pod70 on October 02, 2017, 08:38:04 AM
I think it might be your CDI - I had one recently which would be fine for a few miles and then something would overheat and break down. Once I got back to workshop and the unit had cooled, everything would be fine. Eventually you'll get to a point where the bike will start backfiring and refuse to start at all

Unfortunately it's the electronics that always let you down on these old bikes :(


Title: Re: Trouble starting - Power loss - Cut off
Post by: a_morti on October 02, 2017, 09:02:40 AM
Regulator is easy to check. Get yourself a multimeter if you don't already have one.

Cdi less easy to check, but very easy to swap out.

What kills cdi is sometimes just age/vibrations, but mainly over voltage from a faulty charging system.



Title: Re: Trouble starting - Power loss - Cut off
Post by: a_morti on October 02, 2017, 09:04:36 AM
Considering you've just had a dead battery, I'm going to go with charging system, as over voltage can fry them while under voltage can leave them dead too. Cdi could also be gone, but if so then as a symptom of charging system.

This is going to require some actual mechanic work to solve. GET A MULTIMETERS and diagnose it properly before swapping out parts and hoping again. Like I mentioned way up there.


Title: Re: Trouble starting - Power loss - Cut off
Post by: titsonfish on October 07, 2017, 07:20:46 AM
Thanks for the advice. Got a multimeter now and commencing the checks on all wiring. Nothings worked up till now and it's made ever more difficult that the problem is sporadic.


Title: Re: Trouble starting - Power loss - Cut off
Post by: Dash on October 07, 2017, 07:29:02 AM
Thanks for the advice. Got a multimeter now and commencing the checks on all wiring. Nothings worked up till now and it's made ever more difficult that the problem is sporadic.

Those issues are the worst. You'd almost prefer the crankshaft smashing through the cilinderwalls. At least then you know what the issue is. Electric gremlins are the worst.

Good luck man.


Title: Re: Trouble starting - Power loss - Cut off
Post by: titsonfish on October 10, 2017, 04:48:01 PM
Problem solved (time may yet prove me a liar, but all has been going well for a couple of days) turns out it was corrosion of the kill switch connectors which caused it to sporadically activate and earth the electrics through the frame of the bike, causing rapid power loss and random shut off of the engine.

Hope this helps others.


Title: Re: Trouble starting - Power loss - Cut off
Post by: a_morti on October 10, 2017, 06:27:19 PM
Good find!
I once unearthed a dead spider from same location which had been causing an intermittent circuit. Took a while to find that one.


Title: Re: Trouble starting Power loss Cut off
Post by: RVFRick on March 31, 2018, 09:21:55 PM
Ok wanted to give an update. After bypassing the cut off switch, changing batteries, extra cables, grounds and a new LT4 starter I still had the trouble. Got a tune for the car and it has yet to not start since, Even if the battery is weak and is draggy cranking it will still start in a couple spins. After digging in the old tune the injectors were set on 42lb, However I have 36 lb. Now it makes sense. The PCm may have not fired the injectors enough for starting if set like this, but I may be wrong. Either way it starts and runs good now. Thanks

Injectors? Surely you aren't talking about a normal CB-1.


Title: Re: Trouble starting - Power loss - Cut off
Post by: Dash on April 01, 2018, 08:45:20 AM
Did someone shove a Hornet engine in there? Injectors didn't excist back when the CB-1 was born  ;D


Title: Re: Trouble starting Power loss Cut off
Post by: a_morti on April 01, 2018, 11:31:43 AM
Ok wanted to give an update. After bypassing the cut off switch, changing batteries, extra cables, grounds and a new LT4 starter I still had the trouble. Got a tune for the car and it has yet to not start since, Even if the battery is weak and is draggy cranking it will still start in a couple spins. After digging in the old tune the injectors were set on 42lb, However I have 36 lb. Now it makes sense. The PCm may have not fired the injectors enough for starting if set like this, but I may be wrong. Either way it starts and runs good now. Thanks

Injectors? Surely you aren't talking about a normal CB-1.
Every post he's made is nonsense then he hits us with a link to a non relevant FB page. He can take a walk.