07 EC250 stalls & starts only with choke
 

Hi guys, I am hoping you will be able to steer me in the right direction. I have had a couple of days trail riding on the bike now and have find that it will not idle for more than perhaps 30 seconds before the revs start to drop and the bike dies. When restarting, even when hot, I find that I often have to pull the choke out to get the bike going again. I can kick until I am a sweaty mess, having tried with both open and closed throttle, but all it takes is for the choke to be pulled and after a couple of prods the bike will usually start and I am off again. Are they likely to be linked issues? The carb has been stripped, cleaned and rebuilt by a bike shop, with the mechanic being a middle aged lifelong MX racer, so I assume he knew what he was doing. Any suggestions would be gratefully received. Cheers San

Because it only starts with the choke even when warm it sounds like it is lean. I would turn the idle air screw in one half turn and see if it gets better. If it does get better but is still not correct you can try to turn it in more. If its happy point is less than one turn from the air screw from being seated you should go one size richer on the pilot jet.

Thanks for that, will give it a go and post back