Motor Car History
 Veteran - Vintage - Classic - Modern
Motor car history
Understanding the Automobile
Toggle Navigation
  • Home
  • Makes and models
  • Motor car History
  • Motor Car Guide
    • Induction & Exhaust
    • Tyres wheels Brakes
    • Vehicle Body types
    • Electrical & electronic
    • Gearbox & Drivetrain
    • Engine Components
    • Suspension Types
    • Engines
  • Trivia
    • Advertising
    • Race events
    • Film & TV
    • Museums
  • links
    • Advertise your business
    • About us
    • Help with a donation
  • Log in
  • Register
  • Advertise
  • You are here:  
  • Motor Car
  • Motor Car Guide
  • Induction-extraction
  • Carburettor dashpot oil top up Guide
  • Motor Car
  • Motor Car Guide
  • Induction-extraction
Categories
Induction-extraction
Technical Guides

History

Topping up the dashpot oil level

Topping up the dashpot oil level

Guide Carburettor dashpot oil top up on SU and Stromberg carburettors.

Guide

Tools needed

  • Correct oil for make
  • Rag to clean
  • Grips if lid (screw top) is very tight
  • Torch or light to check level if bad lighting

 

Time: 15 mins
Difficulty: very easy


The SU type carburettor has a tapered needle that slides in an adjustable jet to increase or decrease the petrol flow. The needle is attached to a piston assembly which slides and down the suction chamber.As the throttle buttefly opens, air is draw in through the piston assembly from the suction chamber the piston, the piston rises lifts the tapered needle out of the jet, and increases the oil-filled damper assembly in the top of the suction chamber and limits the speed at which the piston rises.
If there is no oil in the damper, the piston will rise quickly causing engine hesitation and stalling. check the damper oil-level regularly and top up if necessary.

Topping up the dashpot oil level

Unscrew the cap on top of the carburettor suction chamber Damper cap lift and withdraw the damper unit.

Pour in light oil SAE 20 on SU carburettors, and a special Zenith dashpot oil on a Stromberg CD unit.

Fill the suction piston guide rod to within 1/4 in (6.35mm). of the top of the rod. Gently replace the Damper Guide rod damper, push it slowly down and screw the cap fully home.

Topping up the dashpot oil level

Check the action of the piston by lifting the air valve through the air intake opening. It should resist the lift and rise slowly under pressure if the oil is at the correct level and the damper in good condition. If not, fit a new damper assembly.

Topping up the dashpot oil level

Related

motor car on you tube

Also read (Members)
  • Carburettor cable lubricating controls
  • Carburettor linkages Lubricating and adj...
  • Exhaust manifold Checking hot-spot valve
  • Carburettor dashpot oil top up Guide
Carburettor related | SU carburettor | Stromberg carburettor

Can’t see this article ?  >>  Register here. <<

Read more in this section (Registered)

Exhaust manifold
Exhaust manifold
Read more...
Classic Car Air filter Replacement
Classic Car Air filter Replacement
Read more...
Inlet Manifold
Inlet Manifold
Read more...

Back to Top

© 2023 Motor Car History