What the hell is going on with my bike!?

[Xander]

I bought a GPX250 recently and after about 2 weeks of ownership I'm overall ecstatic with my bike. Once it gets going its right as rain.

Trouble is getting started.
Sometimes when I try to pull away from a standstill I rev it and slowly let the clutch out. You'd expect the bike to pull a head, but instead the revs DROP sharply to almost zero as soon as I let go of the clutch.

Try again - rev, let clutch out, BAM revs drop.
Try again - rev, let clutch out, BAM revs drop.
Try again - rev, let clutch out - away she goes right as rain!

What the hell is this? It's happened a few times that I'm in the car park reving it and trying to ease out the clutch over again for a solid 30 seconds, looking like a complete moron.

This ONLY happens when I start on a drive, when I pull up to the lights etc its fine. Even if I put it in neutral at the lights.

Also when its doing this thing, I cant click up into second.

What could the problem be and whats the cheapest realiable way to fix this?

[Bart]

Prob just needs to warm up a bit mate. Mine runs like a bitch when she first starts too.

Or maybe ya spark plugs are dirty if it takes longer than normal. take them out and give them a clean or replace

[chidding]

Sounds like your stand kill switch thingymabob

maybe after your initial mucking around it knocks it abit

[taint]

What year, how many km's. When was the last service (oil change)

[thro]

Yeah sounds like you need to let it warm up first with the choke.

How i used to start off with my zzr (same motor)

- half choke
- start bike
- rev to 4000-5000 rpm with throttle, and gradually wean off choke
- blip throttle with no choke as soon as you can wean it off, to keep it running
- front brake on, clutch in, select first gear holding revs at about 4000
- pull away with plenty of revs

generally by the time you get to the first intersection/place to stop it should be warm enough to run properly without the rooting around.

Carbies... hate em

[Sairz]

i agree with thinking it's the side stand kill switch thing-o playing around wi ya. sounds too much like what my ol' zzr used to do when forgot to put up the stand :rollseyes: ..but it would just stall

...but if your stand is up then maybe it's a bit dodgey.

[Xander]

Thanks for the replies guys.

I think maybe the kill switch for when the stand is down could be spot on. There also might be some sort of loose connection because sometimes when I put the stand down it shuts the motor off, and sometimes it doesnt.

Good ideas about the warming up issue, I should have been more clear in my description of the problem.
I had suspected the warming up issue too, but even when the bike is definitely warm it has done it. When I engage the clutch its like the motor just cuts out. It doesnt give ANY pull at all.
Either the motor is electronically shutting off, (some sort of override perhaps, like for the example a faulty stand kill switch) or something with the clutch is just 100% not engaging.

I sit there revving it, 5 or 6,000, let the clutch out and the revs just drop to basically stalling point, (and about half the time it actually stalls). There is no pull on the chain whatsoever.
Rinse and repeat, then suddenly something happens, the motor spins, the clutch engages and the bike lurches forward and drives perfectly normally.

Anyway I'll bring it to a bike shop tomorrow and get them to have a squiz.

Thanks guys.

[FJ Steve]

I reckon it's Psyched inflicting bad joo-joo on you because you stole his avatar Perth Street Bikes - View Profile: Psyched

Oh...and check the operation of the side stand switch...could be faulty wiring in that area.

[Xander]

Well I sacrificed a small animal to the God of Psyched and it looks like he has forgiven me.


Turns it was the switch on the side stand.
I only bought the bike 2 weeks ago, before that it had belonged to a lady who had it sitting around for most of the 2 year period she owned it for.

So the little knob on the switch had become very stiff and it took maybe 30 seconds for it to slowly slide and grind its way out of pressed in "side stand is down" position.
So for that time the motor was automatically shutting off every time I tried to let the clutch out.

I sprayed some WD40 on there and gave it a few good pushs in and out. Now its right as rain, pops out straight away and the bike's computer says "yep stands up, lets go"


Thanks for the advice guys.