GN250 Help needed

[Free to Ride]

Hi
My Suzuki GN250 which is 1 and a half years old wouldnt start on Friday night after I had put petrol in it after riding it for half an hour. I jumped started it and then got 15kms down the road when it died.
It has a brand new battery - 3 weeks old, fully charged. It has just come back from the bike shop twice for the same thing - stopping when I am riding it and it is still happening. If I take it back to the bike shop I'd like to have some idea what is wrong.
plus no fun being stuck in the middle of nowhere in the dark.
If anyone has any ideas Id be really grateful.

[ldnz]

You say jump starting got it going - so I take it its not turning over from the starter? Does the headlight come on with the key as usual? Is the spark plug lead firmly on the plug?

Give us some more info, and im sure we'll be able to give you a reasonable idea.

[terbang]

You mention the battery was fully charged, have you been having flat battery problems lately..? The ginnys are the old style fixed magnet and wound stator (or vice versa)type alternator controlled by a basic R/R (regulator rectifier). They generate heat and need a good battery at all times or else they can generate too much heat..!
But there could be a multitude of sins happening so more info please..?

[Free to Ride]

Okay - im not mechinical savvy, so I shall try to describe in layman terms what is wrong so bear with me.
The bike was parked up for a few months over winter, and when I went to use it in January it wouldnt go, no charge on the button that you click to start it. I got the bike shop where I bought it from to come and get it, and fix it. So they did (they recharged the battery, and gave it a service - change oil filter etc.). When I went to use it a week later, it started easy so off I went to work. I got 10kms down the road, and it backfired and stopped. I checked the petrol, and there was petrol in there. So the bike shop came and got it, and charged the battery, and told me it was fine. The next time I used the bike a couple of days later, I got 25kms from home and the bike did an enormous backfire and stopped again. No power. the lights still went, a bit dim, the indicators still went as well.
Anyway rang the bike shop again - (which is costing me a damn fortune which is why Im asking for help here). and they came and got it, and charged the battery and told me it was okay.
Well it wasnt - went to a place and got a new battery, and yes it is in properly! Used the bike on Fri night and it died at the petrol station, so we managed to jump start it, and it only went for about 10kms before backfiring again, and no power in the engine. The lights are still working, but the ignition(?) wont work.

[Free to Ride]

anyway the nice motorbike guy who stopped and had a quick look tried to get it to go by running with it, and it wouldnt start, he checked the connections and he couldnt find any loose ones.
So I just need some ideas so when I take it to a different shop I sound knowledgeable.
Thank you for reading this far anyway.
The bike at the mo is stuck in Levin. So if there is a good mechanic down that way maybe someone could let me know please.

[changing_man]

I had a similar problem with my (bought from new) GN (amongst a multitude of other problems). We eventually tracked it down to the alternator being stuffed, so that the battery was not being re-charged whilst riding. To my novice brain, your problem might be similar - new battery that keeps going flat.

[Free to Ride]

the alternator - thank you - at least it gives me some idea.
I feel like ive missed out on the best part of summer riding!! do you remember how much was yours to replace

[changing_man]

I had the GN in the shop about 10 times in 9months, all under warranty - so no cost to me other than time and frustration. Despite being a brand-new bike, it was not uncommon to find that bits of the wiring were so aged the plastic/rubber was completely fatigued and brittle. For example, those little clear plastic sleeves they put over the connectors? Yellow and would rip when you pulled on them. Gave the impression that they had salvaged bits off the workshop floor etc.

I took it for a ride from Akl to Waitomo the Friday evening 3 days after buying it, and ended up stranded by the side of the road with no headlight. The main bulb would blow regularly.

The worst of the experiences was riding from Whangerei to Auckland with a 5am start in the dark - wanting to get to Akl in time for work. The alternator problem was there but as yet undiagnosed, and as I rode the battery got flatter and flatter and the headlight got dimmer and dimmer, until at about 6am I was riding in the dark basically on night-vision. Of course, oncoming cars would come round the bends on full beam, blinding me and destroying all hope of being able to see where the road went. I ended up parking (at the top of a hill so I could jump-start it by rolling) until dawn came and I could see where I was going. Had to stop for fuel and flag a car down to jump-start it at one point. I was late for work but felt lucky to be alive - and desparate to get my full license so I could get rid of the GN.

[Turtle]

Ive had a few of these shit the voltage regulator not that long after selling them.Get yr shop to check the alternator output....My moneys on the v/regulator.

[Steam]

I would say it's cos your battery isn't charging. On a GN250 the battery runs everything, the lights and sparkplug too. No charged battery, no spark.
THings that can stop a battery charging are; fused generator coils (stator), or regulator broken, or loose wiring, or old battery. Since your battery is fine it sounds like one of the others.

The backfire is caused by the bike missing because there isn't enough electricity to make a spark every cycle. This causes unburned fuel vapour to build up in your exhaust. When the electrics muster enough power to finally cause a spark, the fuel in the exhaust pipe also detonates, causing the backfire. Clear as mud?
That's my take on it anyway.