probable regulator / rectifier issue

[budd]

I'm pretty sure the reg / rectifier as failed as the battery doesn't seem to be charging whilst riding and gradually loses it's charge, I had to get a bump start in Douglas last week at the Manx GP, after that I was charging it for a couple of hours the night before the next days ride out, the battery takes the charge from the charger no problem and it spins it over well straight afther charging but after 50 -80 miles it struggles or fails to turns over enough to start it, does this sound like the reg? I've read about the battery been fired but this doesn't seem to be the case I've yet to put a multi-meter across the battery to check charging voltage (which should be 14v ish) if it is the reg I've also read the the CBR 125 item is a direct replacement, is their a specific yr CBR I need ? will a 2004-07 one fit ?

[Wicky]

Seems a run of late on toastie R/Rs - Is yours an early unfinned version?

Try one of these >> http://www.ebay.co.uk/itm/HONDA-CBR125- ... 500wt_1166

[budd]

early un-finned

[vtrjames]

do the basics too, check the wiring harness and check the alternator windings just in case. the manual says 0.2 to 0.5 ohms at 20 degrees.

[budd]

do the basics too, check the wiring harness and check the alternator windings just in case. the manual says 0.2 to 0.5 ohms at 20 degrees.

will do only got back from the IOM last night so I just unloaded it from the van and parked the bike in the garage I'll check the current across the battery and also the windings but I figure I may as well replace the reg as a matter of course, it's the old original un-finned one and is 16 yrs old so I could consider it a service item.

[the exile]

I've been having this issue the last 5 months thinking the worst, RR, battery, alternator.
I bought a new battery, fired up beautifully but on a stop start petrol fill the engine was sluggish to start. WTF ?
Check the bolt securing the live wire on the starter casing (under a rubber hood), mine was corroded to fook creating massive resistance to any current trying to get through and killing the battery.
I posted about this yesterday and following the excellent board members advice I changed the starter motor bolt for free and now I can't believe the difference.
Sorry if you've done this already, but if you haven't you may be surprised.
Ged

[VTRDark]

but on a stop start petrol fill the engine was sluggish to start. WTF ?

This can be caused by over filling the tank. If it is filled over the breather bar that goes across inside the tank it fills with petrol which can cause a vacuum lock which can make it sluggish to start or run rough.

(:-})

[scott02464]

but on a stop start petrol fill the engine was sluggish to start. WTF ?

This can be caused by over filling the tank. If it is filled over the breather bar that goes across inside the tank it fills with petrol which can cause a vacuum lock which can make it sluggish to start or run rough.

(:-})

Oh is that what that bar is ha! I do always fill up to this but never known its part of the breather.... :-(

[leevtr]

but on a stop start petrol fill the engine was sluggish to start. WTF ?

This can be caused by over filling the tank. If it is filled over the breather bar that goes across inside the tank it fills with petrol which can cause a vacuum lock which can make it sluggish to start or run rough.

(:-})

Oh is that what that bar is ha! I do always fill up to this but never known its part of the breather.... :-(

I always brim mine, and have never had this problem.

[Rob]

Always brim mine too.

And on Saturday Al, (AMCQ46) sat on his so he could really fill it up and I wouldn't describe him as sluggish

Not that I'm saying it's not be a problem, just never experienced it

[lloydie]

I brim mine to never had a problem

[AMCQ46]

Always brim mine too.

And on Saturday Al, (AMCQ46) sat on his so he could really fill it up and I wouldn't describe him as sluggish

Not that I'm saying it's not be a problem, just never experienced it

Yup I always fill it right to the brim and with the bike upright, you miss out on 0.5l if you fill it on the side stand. Never had any vac lock problem

[VTRDark]

Yep both Seb and myself had a problem with it once from overfilling, and there's plenty of mention of it on the hawk site with the solution to re open and close the fuel cap. I will find some threads on it. I generally fill up to the bar with the bike on the sidestand but never over it. I may be wrong but IIRC I think there may even be a mention of it in the user manual somewhere about not overfilling.

Here's a recent one by Hawkrider http://www.superhawkforum.com/forums/te ... sue-29218/

Very likely that this loss of power and smell of gas has happened shortly after fillup. If you go above the tube that you see in the tank you will likely get gas in the vent line. The way the vent line is routed causes that fuel to be trapped and a resulting vacuum lock in the tank. Simply opening the filler cap allows the fuel to drain out of the tube on the left lower by the motor. This is where your smell of gas is probably coming from. So, don't fill the tank all the way up and don't wheelie or stoppie shortly after filling up.

and 841Hawk http://www.superhawkforum.com/forums/te ... ded-28717/

These two things are the answer..... you overfilled the tank which caused the vent line to become blocked.

When you opened the tank you released the vacuum lock which then allowed the float bowl to refill and the bike to run normally again.

and one more from Superbling http://www.superhawkforum.com/forums/te ... ions-7619/

If you fill the tank up too much which almost everyone does to get a liiiiiitle more range, the vent tube is blocked/stopped causing the petcock to pull a vacuum on the tank which eventually stops fuel flow. Engine sputters for a bit and then dies from lack of fuel to the carbs. Open tank for a couple of seconds/close, restart, and next time don't fill it up so high!

I'm not grabbing any more.

(:-})

[edds11]

Don't forget that the american bikes have the PAR system (vapour capture) and all that baldrocks, thats maybe why they have a problem.....just a thought

[Rob]

Seems strange.

If it's a vent tube them it vents to atmosphere? Either petrol (sorry gas) would just escape down it freely or those huge carbs would just suck it back up.

The only vent tube I'm aware of is on the outer rim of the fuel filler so when you overfill it pisses petrol all over your boots. Not that I've done it....

Edit.

Also, if there is some vent line high up in the tank does that mean we can't lean the bike over until it's nearly empty? Maybe that's why it's not good on fuel, everytime you go around a corner the petrol is running out of this vent all over the road