Kangaroo problem on CBF125

[Adam_M]

Hi all,

Before my first service on my CBF125 I had the 'kangaroo problem' occour twice, where on a hot day the bike just dies, which for me happened when stopped in heavy traffic. This guy explains the problem very well: http://cbf125rider.wordpress.com/2011/06/27/the-dreaded-kangaroo-hopping-problem/

Now when I took it in for it's first service, I mentioned this and their solution was just to fiddle with the ECU. Now I haven't had the problem since but I have changed my route to avoid standing traffic, most importantly my MPG has gone from 122 to about 95-100. Absolutely NOT acceptable, and frankly they seem to not want to deal with it, and I want that MPG back.

So what should I do, take it to another hopefully more useful Honda dealer or give Honda themselves a call about it? Anyone else had the same problem?

Thanks,

Adam

[Weebl]

From what he has written, and what you have written it seems the problem occurs because the bike runs too lean in hot weather.

It sounds like they have turned the fuel up to compensate, you can't have it all ways, you have had the bike richened up to stop it running rough, but you want more MPG. The only way to get that MPG back will be to run lean again, which will cause overheating and premature engine failure.

If you are adamant, take the bike back and insist they undo what they did to alter the fueling. I expect they will but when you go back and complain you have holed a piston they will just nod and say 'yes'

[Adam_M]

From what he has written, and what you have written it seems the problem occurs because the bike runs too lean in hot weather.

It sounds like they have turned the fuel up to compensate, you can't have it all ways, you have had the bike richened up to stop it running rough, but you want more MPG. The only way to get that MPG back will be to run lean again, which will cause overheating and premature engine failure.

If you are adamant, take the bike back and insist they undo what they did to alter the fueling. I expect they will but when you go back and complain you have holed a piston they will just nod and say 'yes'

 

If that's the reason and it's the only option then I'll accept it, I suppose 90-100mpg isn't utterly terrible, though I spent more to get this other another bike to get more MPG as I'm riding over 10k miles a year just to get to work.

Would this explain why every so often the bike seems to miss a beat and jerk back? another minor problem I've had with it, I had assumed it was either due to the pump not allowing enough fuel in or just something that normally happens on single cylinder bikes.

[Weebl]

If that's the reason and it's the only option then I'll accept it, I suppose 90-100mpg isn't utterly terrible, though I spent more to get this other another bike to get more MPG as I'm riding over 10k miles a year just to get to work.

Would this explain why every so often the bike seems to miss a beat and jerk back? another minor problem I've had with it, I had assumed it was either due to the pump not allowing enough fuel in or just something that normally happens on single cylinder bikes.

 

100MPG is quite good I would have thought, I know my sons 125 gets nowhere near that (but it is an Aprilia RS125 so it is to be expected)

Maybe ask around other owners (preferably one's without the kangaroo problem) to see what their average MPG is? If they happily get 120 with no issues then maybe the garage have masked the issue by turning it up too rich to help with an underlying fault? What is the quoted average MPG, and how do you ride it?

It should not really miss, once in a blue moon I suppose you can put down to whatever, but if it does it regularly then you might want to investigate the cause. If it is the fuel pump not supplying enough pressure then you need to get it investigated, as a lean running engine will destroy itself very quickly, detonation can happen in an instant at high revs and will easily blow a hole in a piston.

Hm, I have just checked the official Honda figures and they vary from 130 to 160MPG (which is ridiculous) MCN did a review and their actual returned figure was 87.5 which makes your 90-100 sound pretty good?

Did you ask the garage exactly what they did?

[Adam_M]

100MPG is quite good I would have thought, I know my sons 125 gets nowhere near that (but it is an Aprilia RS125 so it is to be expected)

Maybe ask around other owners (preferably one's without the kangaroo problem) to see what their average MPG is? If they happily get 120 with no issues then maybe the garage have masked the issue by turning it up too rich to help with an underlying fault? What is the quoted average MPG, and how do you ride it?

It should not really miss, once in a blue moon I suppose you can put down to whatever, but if it does it regularly then you might want to investigate the cause. If it is the fuel pump not supplying enough pressure then you need to get it investigated, as a lean running engine will destroy itself very quickly, detonation can happen in an instant at high revs and will easily blow a hole in a piston.

Hm, I have just checked the official Honda figures and they vary from 130 to 160MPG (which is ridiculous) MCN did a review and their actual returned figure was 87.5 which makes your 90-100 sound pretty good?

Did you ask the garage exactly what they did?

 

MPG wise I've seen everything from 110 to an utterly crazy 180! so I'd say mine is performing slightly below the norm. That MCN test is the only one I've heard below the hundred mark, a strange one that one.

I did try to find out exactly what they did but they were not very helpful at all, I don't think I'll be going there again and I'll take it elsewhere for the next service and tell them exactly what's happened so far and hopefully I'll get some peace of mind.

The instant explosions don't sound fun at all! So I'll get that looked into ASAP. I definitely got more performance after they messed with the ECU however, which might not be a good thing in the long run by the sounds of it.

[argentum40]

personally i would rather use abit more fuel than running the engine lean and on the edge of destruction... i run my 2 strokes slightly rich for that very reason and with the little 100 i hammer it all over.... no issues whatsoever because the carb is upjetted... now if i did that running lean the engine would have holed a piston by now...

you mention the performance has improved which is the bonus of what they did.... if you want to increase your MPG upshift at lower revs and ride it slower... most modern 125 4 bangers couldnt pull the skin off a rice pudding anyway