carbie question

[fosinator]

Hi i have a silly question but my carb has four adjustment screws on it.I was thinking all three on one side were HS,LS,Idle but theres another on the moving throttle slide which on the beginners guide on this forum says idle but i dunno what it does.Maybe a secondary idle screw not that theres any point i suppose.Has anyone else got 4 adjustment screws on their carb?I did stupidly fiddle with all of them but now dunno where I'm at.Its a .30 engine so i was gonna try some base settings for a .28 cos thats all i could find.cheers in advance.

 

[Metalhead Matt]

The needle where the fuel line attaches is the high speed. The lsn is on the carb barrel(part that moves when you give it throttle). The idle screw is what holds the barrel open enough to let the engine idle. It usually has a little spring underneath it. The other screw is probably a mid speed needle, which is never supposed to be touched.

 

[olds97_lss]

This has a couple photo's of a carb with descriptions of the needles (post 2):
https://www.rcnitrotalk.com/forum/showthread.php?t=60832

If you have a needle on the end of that silver part in the far left of the first photo, that's your mid-speed that MHM is talking about.

 

[fosinator]

thanks guys for the info i can start to tune now i know what screw does what