Screwing IN the mixture screw reduces fuel flow - correct ? or is it opposite what you might expect ?

The reason I ask this is because the Yosh comp full instructions say to go 1 turn from all the way in and the Dyno Jet instructions says 3 turns from all the way in.....

What portion of the carb operation does the mixture screw most greatly effect ?

Thanks, just a bit confused !?

 

I have, well had an FMF pipe and went with the 3 turns like dyno says and my rap runs great

 

The instructions on the Yosh pipe ARE WRONG!! Don't do it, it won't even run at 1 turn out. And yes you are correct, it reduces the fuel allowed to pass through.

Start out with 3 turns and go from there. BUT..........if you haven't monkeyed with it yet be sure to slowly turn the screws in from their stock position and count how many turns it takes to GENTLY bottom out the screws. There will more than likely be a difference from the right carb to the left. Keep that same stagger when you make your new settings.

The same thing happend to me at the beginning..............belive me when I say that "It won't even start with 1 turn out".

Good luck. [img]i/expressions/face-icon-small-smile.gif[/img]

 

The fuel screw on the engine side of the carb controls the idle mixture and just off idle. It is sometimes called the idle mixture screw. Turning in = less fuel = leaner. Turning out = more fuel = richer.

From what I was told by a mechanic - the way to find out if it is adjusted right is as follows:
While the quad is at idle, rev the engine a little and let off the throttle. If the RPMs go right back to where it should idle - you are good. If the RPMs stay higher than idle for a little bit - you are too lean and need to turn the screws out. If the RPMs drop below the idle speed for a split second and then return to normal you are idling rich and need to turn the screws in. You may want to check with others, but that is how I was told to adjust it. Good Luck!

RR1

 

GregV,

I suspected something was wrong with "1 turn out". I installed the Dyno Jet kit a while ago and went with 3 turns. I recently installed the Yosh and, of course, a month later I looked at the directions. I noticed a big diff so that's why I got confused.

Is it an idle mixture adjustment and does it have any impact on higher RPMs like the needles and main jets ??

 

It is the air/fuel mixture. There is a seperate pilot jet dedicated to the idle function...........BUT, your mains if not the proper size can effect it briefly as RaptorRacer1 said. You will definatly want to do a plug check and there is always the popping on decelleration that is a sign of impropper jetting.

 

OK - I think I got it ! It's running well but I'm always a little uneasy when it runs good on the first try. Plug looked good after duning and no popping on decel so I suppose it's not lean. Good throttle response off idle too. The head pipes (right at the head) like to glow red if your not moving but from what I've read thats OK !?

Thanks gents, Eric