A forum for owners of Yamaha TTR250 trail and enduro bikes!

Long story short.

Choke wouldn't work on a carb I am setting up. Everything else was fine once the bike started and warmed up but it was very reluctant to start.

Took float bowl off and checked the choke and its galleries on the main body of the carb. All looked and worked as they should.

It turned out that the feed from the float bowl to the choke was blocked.

Using a tiny "glasses" screwdriver and a bit of copper wire I was able to clear the blockage and the choke now works fine and the bike starts instantly 

Brian

PS I see that I covered this in my carb rebuild guide here which I had forgotten about