Picked up a 2003 DRZ/KLX110 the other day. Bone stock, one owner. Sat in a shed for at least 2 months.

Got it home, changed oil, cleaned air filter and drained gas and replaced with fresh fuel. Also took off the petcock and cleaned it. No restrictions in fuel flow from the tank to the carb. Got good spark too.

Bike runs, but acts like it is losing fuel flow when the throttle is about 1/2 open. It rev's in neutral ok, but put it in gear and it really bogs down under load once you get to about 1/2 throttle.

We tried cleaning the carb twice (there was some build-up in the float bowl), pulled the jets and cleaned both of them. Put it all back together, but still behaves the same.

I am very mechanically sound, but for some reason, carbs confuse the crap out of me. So, I have no idea how to tell what jets are in there now or even which one is the main jet and which one is the pilot. I assume the big one is the main and the little one is the pilot. In other words, I may need some guidance.

Is this a jetting problem? Any other ideas?

did you run some wire through the jets or just use carb cleaner? there may be some crap still gummed up in the jet. i usually just buy new ones and keep the old ones for spares just incase.

03sik50,

Tried carb cleaner, boiling in some water, then a thorough soak in WD40 and then some more carb cleaner.

I've read in some other posts that I may need to go up a size or 2 on the pilot jet. Does that make sense? I'm not sure how big the hole is through the pilot jet. I can see a pin-prick amount of light directly through the jet. I don't have any wire small enough to get through the thing though.

Cut a piece of stranded wire from whatever you have lying around. Pull a single strand out of the wire and use that to clean your jets. Make sure there's no burrs on it, cut it clean.

Here's a shop manual for the KLX: right click; save as...
It's for a 2002, so there's a few things that might look a bit different in the bottom end, but they all go together basically the same way. Very helpful anyway:

http://boss.csteam.free.fr/Moto/SM_KLX110-A1.PDF

Yea I have suffered a lot of sweat on stupid carburation so i will give you a tip :) Make sure that every port and jet is CLEAN....the more you open the throttle the more the carb uses the main jet if its slightly block it will show signs of bogging down b/c it is not getting enough fuel. Main jet can get blocked(especially when there is no air filter) easy and create problems-AAA1+ to using a small wire-absolute best way i have found....after this....check electrical stuff you possibly have a weak spark(remember just because you have a strong spark outside the engine once that plug is under pressure its a WHOLE other story....)Good luck...oh and make sure there are no suction leaks between the carb and the engine.....this will lean the mixture and can cause an engine to slug....

I wouldnt see needing to change jetting as i assume it ran fine before it was stored away. Try the wire technique or get new jets, I'm sure that will do the trick.

The wire did the trick. Thing runs GREAT now. Thanks for the tip guys!

glad to hear!

Thank you for sharing that PDF manual. I have searched for weeks for that.
Rt