I would like to thank everyone who has posted infomation on this problem.
I bought a 1999 KLR250 2 months ago from a owner who could only start a cold engine with starter fluid and the choke off. I read all the info. here about the enrichment (choke) jet and found mine totally blocked. Carp cleaner and compressed air would not clear it. I could not find a .018 drill in town.
My wifes sewing needle measured .016 and I was able to push it into the jet and cleared the blockage.
It started with the first kick, with the choke on after sitting for 4-5 weeks.
Thanks Again
Ken

 

Try fresh gas and the choke. Empty the carb bowl and let in fresh gas.

 

Over the last 2 months I tried all of these "FIXES" and nothing worked!
Untill I pulled the carberator and cleared the blocked choke jet. Today at
50 degrees out, it started on the 2nd kick.

 

Since I started riding I made a habit of running fuel system cleaner through my bikes (and cars) every so often. Even the cleanest fuel picks up a little dirt eventually and dirt bikes can suck dust into the tank over time. Add to that the various additives in the fuel (from the refinery) that will eventually settle and you will ALWAYS get fuel system deposits eventually. A dose of cleaner once in a while does wonders but you should get several tanks worth out of a regular bottle. Adding too much or using it too often is a waste of money.

 

I am fighting this same problem, except the previous "technician" broke the tip of the sewing needle off in the jet!! Through devious means, I got the jet out of the carb body, but I cannot get the needle tip out of the jet!! If the correct size for the jet is indeed .016-.018 inches, I will source a jet of that size, thread the opening, screw it in and have a beer. The original press-in jet has no numbers or markings that I can see, so I have no idea where to start. Any help will be appreciated.