CG125 (2006) not starting.

[RAYK47]

well done Chris, much more satisfying fixing it yourself. 

[Old-codger]

Well done that man onwards and upwards, Chris you may be interested in the feb edition of Classic Bike Guide there is an article on the Honda CG125 over all the years and the thoughts of many owners.

[ChrisBiggsUK]

You know, if you had told me a few months ago when I started this motorcycling journey that I would be able to do something like change the starter motor on my very own bike (yes, it was an easy job, but that is beside the point), I would have told you that you were a madman.

Well, here we are.  You're all madmen and I'm slowly becoming one of you!

Tomorrow;  Changing the oil and brake fluid.  

I'm a god-like super mechanic!

[Simon Davey]

1 hour ago, ChrisBiggsUK said:

Tomorrow;  Changing the oil and brake fluid.  

I'm a god-like super mechanic!

 

A word of caution with the sump plug....

It's just like undoing any other nut, but you'll be upside down, be certain of spanner direction. 

I'm only saying this, because the only way I get it right is to use a ratchet and socket. This way I can get the loosey lefty bit correct before going underneath. 

 

It's very simple, more simple than the starter motor, so definitely just a word of caution. 

Edited February 13 by Simon Davey

[bonio]

Another word of caution about the sump plug. Don't do a @Westbeefand overtightened it. 

[RideWithStyles]

Fooking Torque wrench it…as a good code of practice, torque everything.

[RideWithStyles]

4 hours ago, Simon Davey said:

 

A word of caution with the sump plug....

It's just like undoing any other nut, but you'll be upside down, be certain of spanner direction. 

I'm only saying this, because the only way I get it right is to use a ratchet and socket. This way I can get the loosey lefty bit correct before going underneath. 

 

It's very simple, more simple than the starter motor, so definitely just a word of caution. 

The word of advice if your very unsure with tightening, place a simple mark with a sharpie on the bolt and case with a arrow to left to loosely or righty to tighty look as you see it from underneath perspective.
 

to tighten go in the loosey direction until it drops or notch towards a full turn (as the tread drops to engages the direction starting point), then go rightly tighty.

this is good for the thread when to engage, a lot less likely to strip or cross thread.

Edited February 13 by RideWithStyles

[Hairsy]

53 minutes ago, RideWithStyles said:

Fooking Torque wrench it…as a good code of practice, torque everything.

 

I'd like to second that. If you've got the bug for doing your own maintenance, invest in a torque wrench. Ultimately, you might need more than one but, for now, I'd suggest getting one that will go up to around 50-60Nm.

 

Spend as much as you can afford but don't feel the need to go too crazy. By the time you've changed your oil, you'll have already saved yourself more than the cost of a mid range torque wrench this week.

 

One over tightening mistake can cost you way more than the cost of a torque wrench.

[RideWithStyles]

Ive got two, both draper I got on sale at different years.

one is a 3/8 - 1/4 drive (goes up to 60 or 90nm I think?) that I use for chain,brakes the small to medium stuff think it might just do a cbf125 axle?

 a half drive think goes above 200nm? for bigger bikes needs like front and rear wheel axles, car wheels etc. 

 

The amount of swearing and anger to stab the mofo with a rusty spoon who worked at a dealership who tightened bolts on way too tight on a golfs airbox, oil filter pretty much everything….

while at rite bike Bradford/leeds the mofos never even looked at a wrench let alone used a torque version, I have to assume they just used the wind.

Edited February 14 by RideWithStyles

[bud]

I have three different torque wrench. But for most bike stuff a Draper 3/8 one like I have will do most stuff.

[ChrisBiggsUK]

I torqued.  I torqued hard!  

 

While hard to tell from the photo, the oil that came out was so black as to have opened up a portal into an alternate dimension and from that dimension a haggard, portly, mirror version of myself peered back.  In that dimension he is still a pedestrian, still having to hoof it everywhere, his weary bones never having a moment of peace and his life doomed to drudgery for all time for in that reality, he never learned to ride a motorcycle.  It was horrible!  

I have put some nice new oil in, given the bike a quick once 'round the block' as it were for the oil to get everywhere it needs to and now put the bike to bed for the evening.

So thats now a new battery, new starter motor, oil change, air filter changed and though I didn't manage to do the brakes today as the kit didn't arrive, they too will be done in due course.

I reiterate from previous posts;  I'm a god-like super mechanic!  And I wouldn't be if it weren't for you fine people!  You're a bunch of enablers.  Terrible, awful enablers.

Never change!

[billysugger]

Judging by the colour of that oil I would probably  have ran some engine flush through before adding the new oil

[RideWithStyles]

Like how you used a plant pot! lol.

oil isn’t too bad, its air cooled single cylinder, if they don’t burn it off first from hard use its gets a little durty.

I wouldnt run an engine flush, fresh oil is a cleaner for the engine, if your concerned just change the oil again before schedule. Its cheap stuff, doesn’t take a lot of it and easy to do.

[Simon Davey]

So much success in so little time. 

Good work God-like super mechanic...

[ChrisBiggsUK]

To bring this particular thread to a close (and hopefully help others in a similar situation in future), a summary;

My 2006 Honda CG125 wouldn't start.  Pressing the ignition merely resulted in a single loud 'click' from somewhere down near the engine.

After trying to jump start the bike, discovered the battery was 20 years old, dead, and couldn't hold a charge any longer.  Battery was subsequently replaced.  This did not resolve the non-starting issue, but the battery needed replacing anyway and this non-starting issue merely brought my attention to the state of the battery sooner.

At the suggestion of one or two people, tried vigorously rocking the bike forward and back while in gear and then starting the bike.  This worked, albeit sporadically, and indicated that it was an issue with the starter motor.
Purchased a new starter motor and fitted it (very easy job on a CG125, may be more difficult on other bikes) and as a result the bike now works perfectly.

It seems that the non starting and single click was (in this instance) starter motor related and as such anyone experiencing similar in the future can (once they have ruled out other potential issues) look at the starter motor as the culprit.  Replacing the starter motor was a very easy job (at least on my CG125 but I assume it would be relatively simple on other similar bikes) and cost me a fraction of what it would have cost to get a mechanic to do it.  If you are able to undo three bolts (in my case I was) then you will be able to change a starter motor.  Look in a haynes manual for your bike (or ManualsLib) and maybe watch a video on youtube and you will see how easy it is to do.

Repair difficulty - Beginner.
Tools needed - Spanner. Coffee/Tea.
Cost of new starter motor (in this instance) - £30 
 

[Mississippi Bullfrog]

Well done. Now you are hooked. 

 

A suggestion....when an engine has had dirty oil in it I never use a flush. They are too aggressive and can dislodge chunks of dirt which then block oil ways.

 

My preferred method is to change the oil more frequently.  Oil contains detergents which clean the engine. The detergents are exhausted long before the oil stops lubricating. So on an engine with an unknown service history I do a few oil changes at somewhere between 1-2k, then extend the intervals until the oil is staying clean for longer. 

 

On bikes I tend to change the oil every 3k regardless. 

 

On one my cars I changed the oil every 5k and at 130k decided to replace the timing chains. A mate who was a workshop manager gave me a hand as we needed to use a 4 post lift to raise the engine slightly.  He commented that the interior of the engine looked like a brand new engine. Everything was clean and golden, not a trace of carbon deposits anywhere. 

[Hairsy]

On 14/02/2025 at 16:34, ChrisBiggsUK said:

I have put some nice new oil in ...

 

Did you replace the oil filter Chris? Apologies if you did but, if not, it's always good practice to replace the oil filter alongside new oil and particularly if the oil that came out was really nasty.

Edited February 19 by Hairsy

[ChrisBiggsUK]

1 minute ago, Hairsy said:

 

Did you replace the oil filter Chris? Apologies if you did but, if not, it's always good practice to replace the oil filter alongside new oil and particularly if the oil that came out was really nasty.

From what I could tell, the oil filter on my 2006 CG is a little mesh sieve eggcup sized thing that was held in by a spring.  When I changed the oil, as the last bits were dribbling out, I cleaned the little sieve with some solvent (per guidance on the internet) as well as cleaning the spring.  I'll be changing the oil again in a couple of weeks time as a precaution, given how filthy the oil was that came out of it.  While I know that the CG could probably run on the oil you could squeeze out of a teenagers face, I want to do everything in my power to keep it running as smoothly and as long as possible.  So, no teenager face squeezing, but another bottle of Castrol in a couple of weeks and see how we go from there.



 

[Hairsy]

2 minutes ago, ChrisBiggsUK said:

From what I could tell, the oil filter on my 2006 CG is a little mesh sieve eggcup sized thing that was held in by a spring. 

 

I've learned something new! In that case, nothing to be concerned about. And great idea to do a further oil change.