GPX 250 issue

[Stace]

Where in Melbourne are you living mate, I'm in Oakleigh and should have all that is required

[Jimmy37]

I'm in Boronia

[Stace]

Too easy mate. Your about 30 minutes max from my place. Let me know when the girl arrives and we'll arrange a time for you to drop over.

[Jimmy37]

Woo that sounds great Stace, thanks a lot, I'll let you know when she gets here. I'm shopping around online for a carb kit, but I can only find ebay ones which im not too sure about can anyone steer me in the right direction?

[Stace]

I'd hold onto you cash for a little while longer mate. By all means do your research but hang of until we check the little beasty out.

[Jimmy37]

I have some more updates on this;

I finally got the bike down here (Melbourne) and she still wasn't starting. I asked my dad to try and kick it over before it got shipped and he said he couldn't get it started either. So I got right into it, and took the carbies out and took them apart. As we had already taken them apart a couple of months previously, and it had barely ran since then, they were quite clean. The jets had a small amount of gunk in them (didn't clean them previously), but other than that, everything was pretty damned clean.

I put everything back in the bike and tryed to start her up, but to no avail. Fuel is definitely getting into the carbs as i unscrewed both drain's in the bowls and clean fuel came out of both. So whats going on?

I can rule out the following;
Carbies are clean
Fuel and fuel tank/tap isn't the problem (clean fuel, new fuel tap)
Throttle cables isn't the problem (were snapped, since been replaced)
Spark plugs are brand new

What else can I try? I'm running out of ideas :/ Any help would be much appreciated

[GPZ_Jim]

you could try cranking it with the plugs out.. see if u smell fuel and while plugs are out see if they spark..

[Jimmy37]

What would being able to smell the fuel prove? that fuel is getting into the engine? I'm taking the spark plugs out again today to do a compression test, ill give em a sniff and the plugs a spark as well.

[Jimmy37]

OK I attempted to take the plugs out again, which failed as I could only get one out for some reason, so I didn't compression test either. The one plug I did get out didn't smell petrolly at all, 'twas slightly oily though.

I'm running out of patience and don't want to venture much further into the unknown in case I do anymore damage to the poor bike, and I have not the money for a mechanic to diagnose the problem.

Any more help/ideas would be much appreciated as I desperately need her up and running. thanks to everyone that's helped out so far

[sempsei]

This all sounds dreadfully familiar. I have a 1991 GPX. In the end we replaced the fuel tap and got a mechanic to re-seat and needle both carbies and sync of course. Fixed.

[Jimmy37]

did your problem prevent the bike from starting though? and do the carbs need to be in the bike to be synced? i am unfamiliar with the process.

[Strika]

Without rereading the whole two pages, have you pulled out the plugs and turned it over to make sue you have spark?

[Strika]

Oh, also, will it run if you spray aerostart down the throttle bodies while cranking it over. That will tll you if fuel is the issue.

[Jimmy37]

Yeah theres spark mate. and no I haven't tried aerostart.

[Jimmy37]

OK, So I have more updates on this. One of the vacuum diaphragms in the carbs had a small tear in it, so I replaced both of those. She then sounded like she wanted to kick over, but didnt have the battery power to do it.

So I went and got the battery charged up today, and still wouldn't start. So i remembered what got it starting previously; disconnecting the choke cable from the carbies.

Well hell it worked.

Although still had the same symptoms: Throttle response = disastrous: i could have the throttle 100% open and it would take a few seconds for her to roar, pumping the throttle open and closed would barely respond. And it was still a bit of a challenge to start her.
A new problem has now arisen, with petrol leaking from what looks like from one of the float bowls (clean fuel mind you) not really bothering me at this point; an easy fix.
I took the fuel line out of the tank and let all the fuel gush out of the carbies, and there was A LOT, and still more came out of the drains when i opened them, so I'm guessing the fuel height is now out of whack.

So i'm pretty sure that carbies is DEFINETLY the problem now. but what should I do? take them to a mechanic to get new needle/seat/sync/fuel heigh done etc? or just buy some good carbs from a wreckers?
Some advice on how to proceed would be much appreciated.