Carb/throttle needle valve adjustment

meowy84

Member
Oh great Happy-Time gurus lend me your wisdom. :) What's a good starting point for throttle needle valve for the first start and the break-in period? I'm finally about to get my Zoom 80/66cc going for the first time and want to minimize the initial hassles. My needle valve has the 5 grooves and the circlip is on the middle one straight from the factory. Obviously since that little valve has a lot to do with the leanness/richness of the mixture I'd rather have it a bit on the rich side for the break-in so I'd rather lift the valve a spot rather than dropping it a spot. Else, leave it in the middle as it is.
 
start from from where it now is , at 24 to 1 mix with syn oil . run ror a few miles & then pull out the spark plug and check the color ,black is rich or or too much oil. try this first
then adjust from there
 
Second notch from the top is a good ball park starting point. As suggested above, after a few miles, a couple of tanks of fuel, check your plug. Very dark indicates a rich mix at which point you might consider raising the 'C' clip a notch but only after a few miles. Two or three tanks of fuel will tell the story better than just a tank full. Don't be afraid to twist that throttle either. Run it hard a few times; it won't hurt your engine and will reduce the break-in time. Running too soft for too long will not help a thing and can keep the rings from setting properly. They're tough little motors and like a little abuse.
Tom
 
I will bump this since I am in the same boat. Dialing in the fuel mix is tricky for a newbie, my plug was definitly on the black and mucky side.
 
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