How much oil do you put in a SU carb?
Fill that inner tube to about 1/4″ below its top. Do not fill above the top of that inner tube. As stated above, overfilling won’t hurt anything but you should develop a feel for how much oil should be in there. Oil above the top of that inner most tube will just get sucked out of the carb and burned.
How do I top up my SU carb?
Topping up the carburettor damper on an SU HIF Unscrew the black plastic cap at the top of each carburettor suction chamber and gently lift the piston and damper up to the top of their travel. Do not attempt to pull it right out.
Can carburetor get oil?
The only way oil can get into the cylinder through the intake VALVE is thru worn or bad valve guide seals (beside a cracked block). The other way excessive oil can get into the cylinder is thru bad or broken piston rings.
How do you clean SU carburettors?
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.
What kind of oil do you use in a SU carb?
SU Carb Dashpot oil. A very good substitute where the genuine SU dashpot oil isn’t available for use in STANDARD spec engines. 20W fully synthetic engine oil – not to be confused with 20W50 engine oil of any sort. Just a ‘straight weight’ oil. I use this on practically anything where any modifications at all change the spec away from original.
What is the viscosity of Mobil 1 15w-50?
Note that, at 0 deg F, the Mobil 1 15W-50 has a viscosity similar to that of a straight SAE15 oil, whereas at 212 deg F, it has a viscosity similar to that of a straight SAE50 oil. Somewhere between those two extremes of temperature, the viscosity curve of Mobil 1 15W-50 must cross the curve for straight SAE20 oil.
Why is dashpot oil not thick enough for SU?
It’s not thick enough. You need a higher viscosity oil to provide greater resistance to upward movement of the piston and needle on acceleration. That causes a bit of “choking” action on acceleration which reduces the hesitation often noticed on acceleration with cars that have SUs.
What kind of oil do you put in a su dashpot?
At the bottom of Page 32, it says: “Use thin engine oil (SAE 10W).” The next recommendation that I find is for my 1965 122S with B18D engine and Type HS-6 carburetors. On Page 62, Note 10 says: “… top up with light engine oil (SAE 20 — not multigrade oil).”