Dashpot Oil

[IndigoBlueMk2]

3.8 Mk2, how far am I supposed to fill the carb dash pots with oil? I fill to the top of the damper bore,is this enough? I notice that there is a hole in the neck of the suction chamber, should it come as far as this? I am having a nasty spitback problem when I accelerate quickly, which has just appeared. Distributor cap and rotor arm are fine (123 ignition). Car is suffering a lack of use at the moment, should I just go out and give it a good run? Car runs lovely otherwise, and always starts after one or two turns, so no problems there. Any help would be appreciated.

[Andy P]

Hi IndigoBlueMk2,
This is taken from the Burlen(SU) web site:

Q: How much damper oil should i use and what type?
A: We recommend using a straight grade SAE 20 oil for the damper in your SU carburettor. This is filled until the level is just below the top of the hollow piston rod. Engine oil will not be suitable as it will be a multi-grade.

Dashpot Oil.jpg (22.03KiB)Viewed 1434 times

Dash Pot Oil 2.jpg (20.13KiB)Viewed 1434 times

Here's the web address for you:
http://sucarb.co.uk/
Hope that heps mate.
Take care.
Andy

[piman]

Hello Indigo Blue MK2,

if the dashpot is overfilled, the excess is blown out through the vent hole if the throttle is opened wide. I found that the oil doesn't disappear that much with time, If there is resistance to fitting the cap from initial replacement then there's enough oil, if the oil level is low then there will be little resistance until it's nearly home.

Yes, give it a good run but a look at the plugs after should give an indication if the mixture is too weak, or see what colour the exhaust tail pipe is.

Alec

[IndigoBlueMk2]

Thanks for your help guys. I filled up the dash pots and took it out today for a good old italian tune up, and all is well with the world. It would seem that the old girl does not like being in the garage for long periods and needs to stretch her legs a bit more often than has been allowed of late. Happy motoring!