Hiya I've got a sherco st300 2016 I was riding one day and everything was fine I washed it started it after a week and floats were stuck managed to sort that cleaned all jets too fully cleaned. Now I have a problem where the bike while rev uncontrollably high with the choke turned on. And will only turn on with choke on. Switch choke off and I can keep it going with blipping the throttle it'll rev high and come back down sound but when I let go it will not idle whatsoever and it feels like the idle screw is doing feck all. 

So to sum it up revs like the ******* is gonna blow up with choke on and then will not idle with it off

Could do with some help cheers

 

 

I would check for a vacuum leak at the intake manifold, and cylinder base gasket by spraying some carb cleaner on those areas while it's running. Mine had a similar condition. It was a failed base gasket.

I think it may be a good idea to re-check the cleanliness of the pilot jet.

Cheers for help people it were reed valve gasket had shat it's pants all good now.