GSXR250 woes

[Brownee]

Hey all
Im having trouble with my bike. its only sparking intermittantly - itl fire fine about 4 times then nothing.
Ive changed the plugs, leads, coils, checked the compression and balanced the carbs just in case. ive swapped out the 'brain' thingee from another wrecked bike that was running but still no joy. the local bike mechanic is stumped aswell.

would anyone at all have any ideas what the problem could be? its been off the road for most of winter now and understandably im getting sick of it.

cheers for any help at all, much appreciated!

ED: i know ive posted this twice i wasnt sure which forum it would get seen best in. cheers.

[Cam_Valk]

Hey.
Explain "itl fire fine about 4 times then nothing".
Are you trying to start it?

[nzspokes]

Replace the pulse generator if it has one. They are hard little bastards to diagnose. But thats the kinda fault they give.

[Brownee]

Hey.
Explain "itl fire fine about 4 times then nothing".
Are you trying to start it?

Yeh sorry when trying to start it. it will turn over but nothing else. so to check its even sparking (as ya do) i pulled out each plug one by one and then watched the gap when turning the motor over. sparked on average 4 times then just nothing more - but the starter motor keeps trying. hope thats a bit clearer?

in the past every now and then if i hadnt ridden for a while i sometimes had to roll start the bike so dont know if that was early stages of the issue coming or not.

[Brownee]

Replace the pulse generator if it has one. They are hard little bastards to diagnose. But thats the kinda fault they give.

hey mate thanks. sorry though, for a mostly half wit like me, whats a pulse generator and where do i find that? the mechanic changed the 'brain' thing - what tells the coils to send the spark - if thats not the same thing?
thanks

[nzspokes]

hey mate thanks. sorry though, for a mostly half wit like me, whats a pulse generator and where do i find that? the mechanic changed the 'brain' thing - what tells the coils to send the spark - if thats not the same thing?
thanks

Its the unit that tells the CDI/ECU (brain) where the crank is and when to fire.

I would put money on it.

[Brownee]

Its the unit that tells the CDI/ECU (brain) where the crank is and when to fire.

I would put money on it.

groovy. its still at the garage so i'll give them a call and see if they can check it out. thanks man.

[neels]

Might be worth hanging a bigger battery off some jumper leads and see if it keeps sparking, could be a lack of volts if it's been parked up for some time.

[Junglesponge]

i agree with nzspokes. i had the same problem with both my gsxr 250s and it all came down to the pulse generators. if you remove them you can see that they have two magnets underneath. Sometimes they can crack causing a disrupted signal which can start ok and then fade like your problem. I would replace those and check all your ground wires too that can cause a weak or no signal.