Triumph Repair: carburetter damper, silicone oil, hydraulic resistance

Question
Hello again Howard, what exactly does the damper do, what happens when the oil is gone and how often should it be topped off? Thank you for all the GREAT information, it has helped immensely with my 79 spitfire!
                                 Steve

Answer
Hi Steve,
The damper serves two main purposes. Since the piston is controlled by air flow, the air flow at idle is pulsating and the piston tries to move with the pulses so the damper stabilizes it. Also since there is no accelerator pump and a quick throttle opening requires extra fuel, the damper restricts the quick opening of the air passage thus forces the velocity of the air to sharply increase and that pulls more fuel from the main jet, thus enrichment of the mixture. The thicker the oil, the richer the mixture on a quick throttle opening. The thicker oil has no affect on steady throttle settings.
The oil also keeps the center post lubed. There is no set time to check the level but it should be checked each time you check under the hood. All you need to do is to unscrew the cap and lift it up about a half inch or so and push it back down. If you feel hydraulic resistance, it has oil in it.
I like good quick throttle response so I use engine oil. Some use ATF and some use Silicone oil.

Howard