Starting issues

[beezma]

Was doing a bit of maintenance on my bike this week, basically i had the tank off and airbox off ... When i put everything back together i managed to get the bike started no issues there... until the next morning i tried again to start it, no luck and whats more fuel petcock was leaking.

Had a look at the fuel petcock, there didn't seem to be anything wrong with the internal seals or the oring, so I assembled it again making sure the screws were tight enough.
With the tank back on the bike and battery fully charged up i tried again to no joy, it would start but as soon as i ease back the throttle the engine cuts out.

Any ideas guys, normally the fzx250 would start first pop with 1/4 throttle and no-choke.

Many thanks,
Matt

Edit: Plugs were fuel fouled, I gave them a good clean but didn't change the situation ( I would assume bike wouldn't start at all if plugs were the problem, am i right?).
Edit 2: I am thinking the idle jets may need cleaned. I'll probably pull carbs later today, unless someone has anything else i should try first?

[frogfeaturesFZR]

Kinked fuel line? If it was starting before you worked it it the problem should be related to whatever you've done. Have you checked all the vacuum hoses to the carbs ?

[beezma]

Kinked fuel line? If it was starting before you worked it it the problem should be related to whatever you've done. Have you checked all the vacuum hoses to the carbs ?

I was thinking the same thing. However vaccum hoses and fuel lines are fine. The only known problem that aroused from when i was doing maintenance was the leaking fuel petcock.
I have removed the carbs and will give them a clean soon, hopefully the problem is simply the idle jets being blocked.

[ducatilover]

Did you pull the carbs apart?
I'd say, check for air leaks.
Is the needle on the carb in properly (under the slide/through the mouth of the carb)
Is the air box sitting correctly?
Are the float heights set right?
Are the intake rubbers on securely and not perished?
What's the idle screw set to?
Spark leads okay with no cracking?
Air line to the petcock on tight, not perished?
If you have removed the carb diaphragms, they may be sitting wrong, giving you a big gay air leak.
Clean the carbs, just to be sure.

With the leaking petcock, check it on a straight edge or mirror to check it isn't warped. (have seen that before, always good for a giggle)
Otherwise, replace the seals and clean it
Good luck.

[beezma]

Did you pull the carbs apart?
I'd say, check for air leaks.
Is the needle on the carb in properly (under the slide/through the mouth of the carb)
Is the air box sitting correctly?
Are the float heights set right?
Are the intake rubbers on securely and not perished?
What's the idle screw set to?
Spark leads okay with no cracking?
Air line to the petcock on tight, not perished?
If you have removed the carb diaphragms, they may be sitting wrong, giving you a big gay air leak.
Clean the carbs, just to be sure.

With the leaking petcock, check it on a straight edge or mirror to check it isn't warped. (have seen that before, always good for a giggle)
Otherwise, replace the seals and clean it
Good luck.

Yes, I am leaning towards the thinking it is a air leak.
Since when I took the airbox off for the second time i found that one of the boots wasn't connected to the carbs properly.

When i cleaned the carbs i found none of the jets were blocked, on some however the hole was a bit small because of crap in it. Which i cleaned out using carb cleaner and a bristle from a broom. Also carb diaphragms, spring and needle were all fine so no "big gay air leak" coming from there.

Now the only thing stopping me from trying to start the thing, is that the boots from the airbox just don't want seat on the carbs. PITA.
So the bike is a fzx250 zeal, are there any tips to getting it on.

[imdying]

Now the only thing stopping me from trying to start the thing, is that the boots from the airbox just don't want seat on the carbs. PITA.

Try using a heat gun (or a hair dryer) on them, warm them up to make them pliable. You won't accidentally get them too hot, they're used to engine heat.

[ducatilover]

If you removed the diaphragms they may not be seated correctly under the top cover on the carbs. An easy way to check is lift the slides in situ. and see if they all drop evenly.

[beezma]

If you removed the diaphragms they may not be seated correctly under the top cover on the carbs. An easy way to check is lift the slides in situ. and see if they all drop evenly.

Wish i had the chance to check that before i took it to the mechanic. Oh well...
I'll let you know what the problem is, when i pick it up.