Here is a picture of my carb off of a ASP 108 2s. What is the small screw on the upper left of the carb. If it is something that needs to be adjusted in there a rule of thumb on how many turns. Thanks

thats the throttle stop screw, the more you screw it in, the less your throttle will close

Isn't that what the one on right does. This is a small screw with a spring around it that is on the left side.

Maybe I will screw it out a little as see if the barrel will close a little more

MetallicaJunkie you were right. Thanks

your welcome.......the other screw is what retains the carb barrel

MJ is correct and the small screw on the right is called a guide screw or guide pin. This screw is not adjustable and has a pin on the end that protrudes into the rotating barrel and runs in the concentric slot cut into the barrel. The action of this pin in the groove when the barrel is rotated causes the barrel to move inward and outward, causing automatic enrichment when the throttle is opened.

Guide screws, throttle stop screws and bleeder screws are often confused on various engines simply because on some, the function of the stop screw and guide screw are combined into one screw and still on others the stop screw has been eliminated altogether.

John

The throttle stop screw is a good aid to bench testing and allows you to have a consistent place to set your idle mix but depending on your flying site you may need to back it off and allow the servo to control it so that the engine can be shut down with the radio.

Incorrect.

The screw with the spring is the air bleed screw (a cheap, low speed 'needle vavle').

The throttle stop screw will also release the carb barrel if it's unscrewed all the way.

Actually MJ is quite correct. That carburator is not a bleeder carb and has no air bleed circuit instead it uses the very common double needle system with the main and mid range needles directly opposed.

The screw on the right is a guide or guide pin screw as already explained and the screw on the left with the spring is the throttle stop screw. Note that on this carb (originally designed by Super Tiger) the functions of throttle stop and guide pin are not combined on the same screw. Each screw has just one function.

John

Thanks JB... I obviously didn't look closely at the pic, I missed spotting the 2nd needle![:@][:@]

Alright, I need my coffee now [&:]

Cool, Oh man I wish my coffee pot would hurry up

Hey John, got the coffee cup in my hand. Looking out the window as I type at about 14" of the white stuff that fell last night. Gee, maybe the postman won't be able to delivery any bills today[&o][&o]

Aw hang the bills! Gotta admit looking forward to the postlady everyday see she, well she digs my airplanes [8D]

Don,t often get the white stuff and get to fly the floats or ski's but make do. Did just get two of the new Kaydet Senior ARF's last week from Nitro that are so cheap. Maybe maiden the first tommorow. This one is set up as a LITE Senior with all mini servos and components that will be a test bed for my New/Old 2.4 Orbit tx and will be powered by a .35AX Ya I know a .35. The battery pack is carried forward next to the engine.

The second is going to take much longer and it will have the wings extended and modified to carry a gallon or more of fuel on floats. Power will likely be a ninety class four stroke.

OK now where did I leave that Geritol?

John