Idles but wont rev up

[BC GZ]

I've been playing with this thing for a couple of days now, it's an 05 with only 560 miles on it and it wasn't running. I've replaced the fuel, replaced the spark plug and taken the carb off and disassembled it and cleaned it 4 times now and it will now fire up and idle but as soon as you touch the throttle it bogs down and dies. Even if you try turning it ever so slightly it just dies. I've tried adjusting the mixture screw and that doesn't do anything, I've worked on lot's of bike and never had any be so stubborn... what am I missing?

[5th_bike]

The manual only mentions 1) clogged main jet 2) clogged needle jet 3) improperly working throttle valve and 4) clogged fuel filter.

Since it idles fine, you could rule out air leaks before the carburetor.
However, when mine is still stone cold, it also has trouble revving up. It needs to be warm to run better and hot to run fine. Did you try starting it (full choke) and wait say half a minute before opening the throttle ?

I'm somewhat at a loss too :??: so please wait until someone else chimes in.

Oh and by the way: Welcome to the GZ250 forum ! :rawk:

[blaine]

Welcome to the forum.Make sure that the carberauter vent tube is not blocked or pinched off.Is the plug in the bottom of the drain tube on the air box?
:cool:

[BC GZ]

I let it sit there and warm up, took the choke off and it idles great but no luck one the throttle is turned. I will go out and check the vent tube now

[BC GZ]

I just pulled the cap off the drain tube for the air box and a bunch of liquid came out, kinda smells like paint thinner so I'm guessing old gas?

[blaine]

Originally Posted by BC GZ

I just pulled the cap off the drain tube for the air box and a bunch of liquid came out, kinda smells like paint thinner so I'm guessing old gas?

Yes,old gas,and blow-by from the crankcase. :cool:

[BC GZ]

Any other ideas out there? I think the filter is fine, i emptied the tank through the petcock. I have soaked and blown air through all the jets and all of the passageways in the carb, I guess it may be possible for a blockage but seems doubtful to me

[blaine]

Originally Posted by BC GZ

Any other ideas out there? I think the filter is fine, i emptied the tank through the petcock. I have soaked and blown air through all the jets and all of the passageways in the carb, I guess it may be possible for a blockage but seems doubtful to me

The filter must be checked from the inside.It can look clean from the outside and be plugged.It draws air from the inside.Always blow air from the outside in to clean.If you blow air from the inside of the filter it will be ruined.
:2tup:

[BC GZ]

Check that one off the list :??:

[5th_bike]

Originally Posted by BC GZ

I let it sit there and warm up, took the choke off and it idles great but no luck one the throttle is turned. [...]

And what if you leave the choke on ? (the same, I presume) :sad:

It still sounds like most likely a clogged jet.