How do you remove a SU carb needle?
(a) Lift off the piston spring. (b) Carefully lift out the piston and needle assembly, and empty the damper oil from the piston rod. (c) Remove the needle locking screw and withdraw the needle. If it cannot be removed easily, tap the needle inwards first and then pull outwards.
How do you adjust a su hs4 carburetor?
Turning the fitting raises and lowers the needle seat. Pick a carb, and turn the fitting 3 flats (1/2 turn), first in one direction, then back 3, then 3 in the other direction. Note where the engine runs better, idle speed should increase. Turn to the best setting.
How do you clean a SU carb?
Check the bottom of the bowl for sediment and remove any by dislodging it with a small screwdriver. Wash out the bowl with clean petrol and wipe dry with a lint-free cloth. Replace the top with a new gasket and tighten the screws evenly. Refit the fuel pipe to the chamber top.
How do you unstick a floating needle?
When the pin is almost out hold onto the float and pull the pin out the rest of the way. With the pin, out the float should be free. If the gas is still on be prepared to shut it off. Gently pull down on the float and which will release the needle valve and the float and valve will come off.
Where does the needle go in a carburetor?
The needle jet—or nozzle as it’s sometimes called—is located in between the main jet and the carburetors venturi. Fuel comes through the main jet and into the needle jet. So the main jet does affect the needle, especially as the throttle opening increases.
How do I know if my carburetor float is stuck?
One of the signs that the carburetor float is sticking is when the engine will not idle. The float is not letting enough fuel into the reservoir, allowing for a constant idle of the engine. The carburetor float is stuck in the closed position, and only a small amount of fuel is seeping into the reservoir.
What does SU carb stand for?
George Skinner together with brothers John and Carl formed the S.U. Carburetter Company in 1910, setting up business in a small workshop in London. The initials S.U. stand for Skinners Union.