RE: Sig 1/3 Spacewalker
Hi Lee,
I have Saito 300 Twin. Believe it or not, the low speed needle has a big effect on the high speed needle.
If the low speed needle is closed too much (too lean) it will affect the high speed to the point that you can take the high neelde out and it won't affect the running. Tell him to open up the low needle about a turn, then go set his high speed needle, tweak to max rpm at full throttle then richen until he sees about a 200-300 rpm on a tachometer, you have to use a tach. The he can drop down to idle and make small adjustments to the low end. After each adjustment go back and check the high end to see if the same rpm is achievable. You have to go back and forth several times before you dial it in just right. You can have a perfect idle and good low speed performance with no top end. The trick is to find the sweet spot that will give you both.
Have fun.
Bob