Just bought a 2012 125 beta evo. Took delivery of it yesterday. Fired it up in the garage and it ran sweetly. Was very pleased.  Gave it a good wash yesterday to make it perfect. Tried starting it after wash and it just kept bogging when choke off. After a while it started to run ok. Thought it must have just been wet somewhere . Then today I fired it up again today. Same again. Starts with choke on but revs are very high with it on. With no choke it dies if you open throttle and just about idles with no throttle. Any ideas ? I've just put in new fuel and a new plug to rule them out. The original plug was very black. Am I going down the pulling carb apart route ? 

 

Also is the air screw that tiny flat head screw on the kickstart side?

Edited March 17, 20215 yr by gazzaecowarrior

It sounds like there may be some dirt in the carb or gloopy old fuel - maybe in the small jet. I'd take the carb off and give it a good clean.

31 minutes ago, markparrish said:

It sounds like there may be some dirt in the carb or gloopy old fuel - maybe in the small jet. I'd take the carb off and give it a good clean.

Just done that. Put compressed air through it. No obvious muck in the bowl but it is now running really well. I'm convinced it was my over zealous jet washing that caused it as it ran great until I washed it.

I notice one of the pink breather pipes nearest the choke runs vertically upwards and follows the direction of the throttle cable towards and terminating by the fuel cap under a plastic cover. Is this the normal route if such a pipe or should it go the other way and terminate near the swing arm like all the others. It just seems vulnerable to water ingress.

I'm afraid I can't help with the breather routing - I guess the tube routes it well away from normal water risk, but you may have blasted some in with your washer. Glad you cleared whatever it was though!