ORIGINAL: MinnFlyer
ORIGINAL: oldvet70
To properly set the high speed needle a tachometer is needed.
Only for some people.
I know MANY modelers (myself included) who never use a tach to set our 4-strokes
I don't disagree as I do it without a Tach at times myself. But for someone just starting into 4 strokes a Tach will help immensely in properly setting the high speed needle.