1.....you have a prop that is too small 16/6 16/8 is closer to the proper size

2....If it's spitting fuel out the exhaust you are too rich!...not too lean! .....turn the needle in...your objective is not to see how far out you can screw the main needle before the engine quits.

3...your idle is too high, with some adjustment to your idle mixture your idle could be 1700-2000 rpm....if you need to idle higher than this.....the idle mixture is not adjusted properly. most saito's come from the factory with a very rich idle mixture. you are most likely rich on the idle mixture if you have not already leaned it out.