Honda CBF 125 engine trouble + management light code.

Hi, I purchased a second hand 2009 CBF 125 around January time, and it ran nicely for around 300 miles, capable of around max 75mph but atleast comfortable at 65, however since then i've had nothing but problems. I've had the fuel pump changed (as i'm aware there was a faulty batch and the garage told me this was the issue), and the fuel injector seal, so once that was replaced the bike ran like new for about 100 miles. However on a long drive on a hot day (around 5/6 hours on off) I felt the bike losing power as it used to. I managed to get home at around 25 mph, and have had problems with it starting up and it's not taking the revs and I can only reach around 40 mph but it doesn't sound healthy and the engine management light comes on after around 15 minutes riding. Takes around 10-15 tries of the ignition from cold before it runs properly, and as I said it just doesn't have any power. For a while it just wouldn't start, due to the battery being dead, I took it back to the garage, and they replaced the battery and air filter. Still however this problem remains. The mechanic seems stumped as to the problem and doesn't know what the engine management light code means.

I'm hoping someone with knowledge of the bike/with engine management codes, could tell me what the bike is trying to tell me. When in neutral with the side stand down, the engine management light blinks twice long, then once short. Then the cycle repeats itself. If anybody has any ideas that could help it'd be appreciated, I have no mechanical knowledge whatsoever so this would really just be to tell the mechanic.

Ps. Sorry if this is in the wrong place etc., new to the site + first post. Thanks

Welcome to TMBF mate.....pop over to the Newbies section and introduce yourself when you can.....

I think you'll need a Haynes manual to work out what the fault code is telling you.....

The flashings means error code 21, I've googled it and looks through pages of stuff and couldn't find a definite answers. You need to get yourself a Haynes manual for it or find somewhere/someone that has one you can look at, the codes will be in there.

Good luck!

I've got the haynes cbf manual In front of me.

If it's code 21 it's:faulty component-oxygen sensor- engine will run

Possible causes: faulty wiring or wiring connector. Faulty, damaged or improperly installed sensor.

Hope the above helps, if you need the other codes let me know and I can take a pic

Thanks

The mechanic seems stumped as to the problem and doesn't know what the engine management light code means.

Sorry Mate he can't be much of a mechanic, that fault code telling him what the fault is and probably how to fix it. He's either not got the diagnostic kit to find it, or he's clueless. Fault codes can be found for any motor through the web these days, suggest you take it elsewhere. I would not ride to long in this state, as you might be doing untold damage.

I've got the haynes cbf manual In front of me.

If it's code 21 it's:faulty component-oxygen sensor- engine will run

Possible causes: faulty wiring or wiring connector. Faulty, damaged or improperly installed sensor.

Hope the above helps, if you need the other codes let me know and I can take a pic

Thanks

That it?

Replace the oxygen sensor then

It's in the cylinder head.

http://www.bike-parts-honda.com/pieces- ... F+125.html

Part number 11. Buy a new one and fit it, or plug the one you have back in properly after a clean. Try that first as it might just be a dodgy connection.

Edit - Where the exhaust comes out of the cylinder, it's above it going into the head. Make sure it is connected and try and remove it, once out, clean it and put it back in then reconnect it. Job done.

I've got the haynes cbf manual In front of me.

If it's code 21 it's:faulty component-oxygen sensor- engine will run

Possible causes: faulty wiring or wiring connector. Faulty, damaged or improperly installed sensor.

Hope the above helps, if you need the other codes let me know and I can take a pic

Thanks

 

That it?

Replace the oxygen sensor then

It's in the cylinder head.

http://www.bike-parts-honda.com/pieces- ... F+125.html

Part number 11. Buy a new one and fit it, or plug the one you have back in properly after a clean. Try that first as it might just be a dodgy connection.

Edit - Where the exhaust comes out of the cylinder, it's above it going into the head. Make sure it is connected and try and remove it, once out, clean it and put it back in then reconnect it. Job done.

Thanks for all the replies guys, been a great help. So would a faulty oxygen sensor likely to cause these symptoms? (Not starting properly/little power). Is it possible the fuel pump could be knackered again? Mechanic checked it when I got the battery fixed and said it was fine, but then again he hasn't been able to fix it so his knowledge might not be great!

As I say absolutely no mechanical knowhow haha! Thanks for all this!

And 125 learner a picture of the fault codes would be great please mate.

If the Lambda sensor has gone it could be causing the engine management system to either richen the mixture or make it too lean.....so it could give the symptoms that you are seeing..... Do as suggested above and see how that goes.....

Either way it's been read to be wrong as the error code is there, which means a new one is in order. So either way it was broken and needed fixing.

If it still isn't right we will get on to what else could be causing it

Bet me to it