ZX2R Shudders and stalls, fuel line problems ???

When i start up my bike it all works fine rides well for around 10 or so minutes n then starts to struggle n jerks when your accelerating. eventually it just stalls for no reason. then it takes forever to start it back up. put a new battery in the other day but yer, need some help. two guys which i was talking to said could be problem with the alternator or dirty fuel lines. the bikes a 91 zxr250 so if anyone has any clue in what to do would be helpfull.

UPDATE:

i pulled bike apart today and fuel filter seems to be clean. battery was flat so i roll started it and bike started but struggled along, when opening the throttle there wasn't much response bike ran for about 45 seconds then started to die, managed to keep it alive for another 20 secs by pulling in the clutch and opening the throttle but this barely made the rpm rise and eventually the bike stalled out then would not start up again.

It sounds almost like the choke could be still on, but I assume it's not. Does it run on only 2 or 3 cylinders? If so, check which headers are running (really hot as opposed to just hot) by wetting your finger and touching it very briefly against the header (or get a thermometer). Post up the results and we'll go from there.

Where are you located?

Make sure you haven't got any kinks in the fuel line when the tank is in place. Also when it start to play up after riding it for a while, have a go of popping the fuel cap open and seeing if the bike will start again (after closing it again of course). If it start OK again then you might have a block in the tank vent.

fuel pump ??

agreed, sound like your breather in your tank is blocked, so when fuel gets burnt air is not replacing it in your tank, therefore fuel is struggling to get into your carbies. could also be a fuel line.
but id try the easiest thing as said before, start till it dies then when it dies open fuel cap (listen for air sucking into tank) and try and start again,,,
see how that goes
cheers

Located in Jandakot

Previous to this the bike ran really well but never really had it out for over 10 mins.
I've tryed opening the fuel cap but had no luck with that.

next thing i was thinking to check is the line between the tank and the fuel filter

they didnt come standard with a inline fuel filter, the fuel filters submerged in the tank on the fuel valve, if it has an inline fuel filter make shore the hoses arn't getting pinched , a torch will help.
if that dont help then check choke is coming off fully. to make it easier take tank off and put a funnell in the fuel delivery hose and keep topping up with fuel so you can narrow down the problem,,,
cheers Tim

UPDATE:

Took the tank off and had a funnel in the fuel line but didn't help it run along. None of the fuel or vacuum lines were crushed and the petacock thingo was clean and all good. When we emptyed the tank lots of black crap came out (the previous owner had the fuel in there for about a year) put everything back together and tryed to start again with no luck tho started motor sounds great.

finally we got the bike running today by a start and it ran good for a while then started to die again.

We're running out of things to check now so any and all new suggestions would be great even if there stupid obvious ones, cos we might have overlooked them

Is it running on all four cylinders?

when the engine warms up, is that when it plays up?
can you rev engine smoother when its cold compared to warm?
have you made certain choke is fully off?

Is it running on all four cylinders?

Yes all 4

when the engine warms up, is that when it plays up?
can you rev engine smoother when its cold compared to warm?
have you made certain choke is fully off?

only runs for around 30 - 40 seconds before getting really bad, so it's not really warming up at all. But for the sake of giving an answer it runs best when first started then it starts to die very fast.

When it did start today we could rev it, but then when it started to die it wouldn't rev even with the clutch in and the throttle open

choke is fully off

UPDATE:

When we emptyed the tank lots of black crap came out (the previous owner had the fuel in there for about a year) put everything back together and tryed to start again with no luck tho started motor sounds great.

Time to clean the carbies........ bet ya the floats sre sticking

problamo fixed o

Cheers to all the game suggestions, we got there in the end.

what was it?

what was it?

The bad thing is I can't answer this question.
Found black crappy hard stuff in the tank. Hoses were clean. Everything else we pulled off seemed fine. The one thing we really did was empty out the tank and the crappy black stuff in it and put fresh fuel in. Put it all back together and it's been running fantastic. Took it for a huge ride today with many stops and had no probs.

While i'm here i've got another question. Should these bikes be running on 98 or 95 fuel ?? I've heard from some people that 98 could damage the bike