My '85 Spree was bogging right at the 25 mph mark. Ran strong up
to 25, then it would hickup. But after some random tinkering
with the carb, and REMOVING the dirty air filter, the thing shot
up to 35 mph. But now after I put in a brand new air filter, I
can USUALLY max around 32-33 mph, but occasionally still
My questions: 1)Are the screws (air/fuel) on the carb just for
idle adjustments, or do they affect overall performance? 2) I
occasionally get a backfire around 25 mph, what can this be a
symptom of? 3) Should I just be happy with the 32-33 max WITH air
filter, or should I eventually be able to get back up to 35 mph
like i was getting WITHOUT the filter? 4)The Scooter usually
starts/idles strong, but sometimes after idling for a 5-10
minutes, it will sputter and die, how come?
I also notice my plug fouls constantly. Every time I check it,
it's covered in black. It's brand new, and I clean it each time,
but should I buy another one? What would cause this?