been a while since i have been on here. I have passed my CBT and purchased a bike. Tis a '96 model SR 125 and looks to be in great condition.

The story is that before the dealer delivered it to me, the battery in the bike was knackered, so he replaced it with a new one. I'm not sure if it was fully charged when delievered.

The problem is that after a couple of days riding the bike has died. It will go for about 10 metres but then starts spluttering  and konks out. All the electrics are dead. What i notice is that the lights (neutral light to be precise) flick on and off when walking it back to the drive way.

So when i get it back to the drive i try to start her up. Nothing happens. I leaver for an hour, then try and i get a mewling from the starter but it doesnt turn over.

The questions: Does it sounds like a dead battery to you?

If it is, why would it happen after ive been out and about?

How does the bike charge the battery when started? is it when the wheels are turning? or just when the engine is going?

Random one....Whats the best fuel for a 4 stroke 125?

Thanks

Rich

________________________________________________________________________

All you people who are just browsing, get registered and get chatting! We don't bite

So the original battery was dead, he replaced it with a new one, and now that's dead, too?  It looks as though the bike isn't charging.  Recharge the battery, start it up, switch on the headlight and watch it as you rev the engine.  If the light brightens as you rev it, it's charging OK.  I suspect it won't, though, and that means that the alternator is somehow not charging the battery.  This could be a fault in the alternator, regulator/rectifier, or anywhere in between.  Not an easy diagnosis, so I would take it back to the dealer and get him to investigate.  A bike with a duff charging system would be regarded in court as 'not fit for purpose', so he has a legal duty to fix it, as long as you present it to him within a reasonable time of purchase.  Batteries do recover slightly when they are left, which is the reason why it will try to start after a short rest.

As to your question: the engine turns the alternator, which charges the battery.  It doesn't matter if the wheels are turning or not.  The alt doesn't put out much power at idle, but will deliver a full charge of around 14v at a 'fast idle' or better.

And your other question: normal unleaded.  Don't waste your money on premuim or whatever - unless you have something very special.  Which you haven't   (It's OK, neither have I.)

--

2003 ST1300 Pan Euro
1995 Yam XT600E
http://goingfastgettingnowhere.blogspot.com/

All you people who are just browsing, get registered and get chatting! We don't bite

On the subject of petrol, I tend to put just the occasional tank of premium in (somewhere between one in six and one in ten fill-ups). My local workshop manager swears by it, or even using four-star if you can find it - the former's supposed to be cleaner burning and the latter contains lead which helps lubricate the engine internals. It's never given me any noticeable increase in power, but I have known it make the bike feel a little more consistent, especially at low speed/small throttle opening. That might, of course,just be a total placebo effect, but, at any rate, it's not doing any harm and that sort of ratio doesn't increase running costs by much...

I also avoid filling up at supermarkets - on a disturbingly large proportion of the (rare) occasions that I have, the bike's felt rough and lumpy afterwards: I've known enough people with cars experience the same thing to believe that there's a reason they can sell petrol that much cheaper than garages...Again, it may just be my imagination, but it makes me feel better to avoid them!

>> ex silens nox noctis <<

Will let you know if Tesco petrol makes a difference in performance.

________________________________________________________________________

All you people who are just browsing, get registered and get chatting! We don't bite

It's also been said (and makes sense) that the cleanliness and integrity of any particular premises' storage tank has more of an influence in determining how good, on average, the fuel will be: in which case a clean supermarket will be better than a grubby branded anyway and it's the luck of the draw as to which will be your "best" local filling-point.

Advanced fuels (Optimax & Ultimate) are definitely different, having a far more significant set of detergents and octane enhancers, both of which contribute to more controlled detonation and clean the engine as they burn. Whether that makes much of an immediate difference probably depends on the state of the engine to begin with and in any case, the higher price can easily offset any benefit gained. Again, I would suspect that it needs to be in fairly regular use to show any real return: although I have noticed the more perky feel to the engine running advanced, that could be because I do use it reasonably often. The only studies carried out on the benefits of advanced have been by the manufacturers, who do make some hefty claims (BP reckon better consumption, Shell claim more power) - so it could be that I'm just believing the hype...after all, there have been any number of proprietary engine "power-pills" over the years which have been apparently manufactured from best-quality snake oil.

Still, on the bright side, even if there is no great difference in quality or performance overall, it's no problem to have a preference based on personal superstitions rather than facts. Rather like having a favoured brand of tyres (I like Bridgestones, myself...speaking of which, I really ought to ditch the Shinko Podiums that came with my RF. Ever heard of them before? Me neither, and I'm not impressed with their somewhat twitchy grip levels under provocation...!).

>> ex silens nox noctis <<

All you people who are just browsing, get registered and get chatting! We don't bite

Well...it'll be some sort of fuelling issue. Always a challenge to make any sort of diagnosis without seeing and hearing it in action. Most obvious question would be whether the idle speed is set correctly. According to the internet it should be around 1300 rpm (but double-check that if you've got any kind of service manual). If you're having to manually keep the revs up to that sort of figure, then the idle speed needs adjusting. There should be a screw on the side of the carburettor to do just that: set it with the engine warmed up.

If you're having to keep the revs higher than that once the engine's warm, then it'd be time to start checking the fuel mix adjustement, clean the air filter and carb and check the spark plug for fouling. (Could even be some of that dodgy supermarket petrol...!) However, if I were you, if it's anything other than tweaking the idle speed I'd take it straight back to the dealer and get them to sort it out under warranty or fit for purpose terms.

You won't do any damage starting in gear with the clutch in, but you won't pass any tests doing that either. I presume this'd be after stalling: when examining they usually like to see you mess about getting into neutral, covering the brakes and doing the Hendon shuffle to keep the bike supported throughout. Just in case - the argument being that unexpected things would happen if you slipped the clutch for any reason while starting up. If nobody's watching, though - it's fine!

>> ex silens nox noctis <<

All you people who are just browsing, get registered and get chatting! We don't bite