Hi:

we have a four stroke 120 SP . After a gallon fuel trhu it, we still can not make it work properly.
If on the bench test bed, in the upright position, and after closing the neddle as much as the tachmeter shows , we get a reasonable consistent high speed. But... at lower speed , say less than 1/2 throttle, it sound badly, with lots of smoke, Too rich even with the small screw completely shifted to the closed position.

Now, we planned to use this engine upside down. IT IS impossible to run it consistently, even with a glow connected from 0 to 30 % of throtle position.

Apprecciate any comment, anwer or WHAT to DO recomendation.
Thanks.

J Attwell
San Luis, ARG.