2002 GZ250 messing with me...

I am helping a friend out with a 03 GZ250. A little back ground, the bike is in good shape and owner said some kids were playing around it. The owner had left the keys in the bike and the kids put sand in the gas tank.

Taking the carb off I could tell someone else had been in it and didn't know what was what. The Jets were all good but the cap on the emulsion tube jet that should have been place through the float bowl was just sitting in the hole in the venture opening.

In the fuel bowl that are three jets, main jet 120, secondary 52.5 and a third emulsion tub jet. The slide is a half moon shape and can only go in one direction. All internal jets were in the correct place but were not clean.

Checked the valves there were good, oil was way too full and there was oil in the air box that needed to be cleaned with more than one rag. Air filter is okay not too dirty.

After cleaning all the parts, draining the gas tank, letting it dry and then hitting it with compressed air, I buttoned it back up. I used a AUX fuel tank with know good gas and fired the bike up, Stated right up and runs good with choke. Once warm will idle well with choke off.

Here is the rub....it will not come off idle with the throttle. Even when the choke is on and high idle, no more rpm change with the throttle, like it is not lifting the slide.

No holes in the diaphragm, slide is fee and moves well. I am guessing that there is not a good seal on the top hat of this carb. It is a plastic top hat with only two screws that hold it down. I am 99% sure that is the issue.

Anyone have any of the same issue and found a fix action for a single carb nightmare? I know the fix action is getting another carb, but come one. If we can bring back our old XJ's from the brink of the grave with 4 carbs...why is a single kicking my butt.

 

3 months old, and not one response..Hmm? @Timbox how this issue end for you/him?

 

I ended up picking up a Amazon knock off carb for around $180. I could not find even a used one for close to that price. New ones I think were going for over $400. It was almost a plug and play. Just had to swap out the end of the choke cable to the new carb choke and away it went.

Didn't need to adjust a thing in the new carb, ran great. So guessing the sand in the tank got into the carb and into the very smll passageways I could not clean inside the carb. I am guessing the transition jet molded space inside the carb was plugged. Either way, the new carb did the trick.

 

Wow, just wow...........

 

@chacal
Once those little passages in the carb were blocked with sand it was done. I tried most things, boiling, B12 chem tool, compressed air, nothing seemed to make it run right with the OEM carb.