Stihl 070 won't rev

[Dazz02]

Right, i've just bought a stihl 070, described as having new piston, cylinder, carb which i would agree with and it all looks good. It idles but wont rev, i then choke it about 1/4 and it'll rev full once at full i can push choke in and it'll still run at full until the trigger is released, another point, the high adjustment screw doesn't seem to be doing anything. Will this be the problem?

 

[Fubar]

it sounds like a carb or fuel delivery problem , i would start at the gas filter and work my way up , i have had stopped up gas filters to act like you just described .

 

[Dazz02]

i put a new filter on made no difference, had an old carb so fitted that, it runs real nice now but my only concern is that to give it a good amount of power the high adjustment screw is almost fully in only about 1/4 turn out whereas on others i've tuned up it should be closer to 3/4 of a turn out. It's running nice at full so hopefully it'll be ok.