simplicity S7 snowblower 7 hp

[bpg 0]

Have a S7 approx. 1971 snowblower (sno - away)with briggs 7 hp. when under load it runs awesome but when not it runs irradically and (sputters and small pops)spits out a small blue flame every so often. Question is, what do I adust to make run smoothly . Carb was (dealer) rebuilt 2 yrs ago but was never tuned after. Any help appreciated thanks

[RedbarnRick 3]

Hi, run it at load and adjust the high speed needle out till it bogs then in till it smoothes out then back it out a 1/4 turn, then do the same under load but at idle with the low speed needle, if this does not help points adjustment would be next.