Carburettor problem

[vibrodolly]

I recently have been experiencing carburettor problems.

Engine dead - turns over, not firing.
Replaces points and condenser several times, new cap, leads. Was getting a spark, but nothing firing.

Turned out to be the large "plunger" you can see when you take the air filter assembly off. It was stuck tight shut - no fuel!

It's stuck at several positions since then.

Any suggestions as to how to make this plunger move more smoothly. The pot has lubrication of the correct kind.

1958 2 door 958 saloon.

Thanks

[bmcecosse]

Unscrew the bell (two screws) and carefully clean the piston and bell internals - try WD40 at first and perhaps a little Brasso just to polish up the surfaces - using NOTHING more abrasive. No abrasive paper or anything like that. Refit and check it rises easily with finger pressure and should drop with a nice clunk. A couple of teaspoons oil in the damper - try engine oil first. Some find 3 in 1 more responsive - but sometimes it leads to 'gasping' when the throttle is opened sharply.

[charlie_morris_minor]

i used 3 in 1 for several years with no problems until i cleaned up the carb inside and out after which it just died when the car got hot, i swapped back to using the recommended oil in the carb and all was fine

[bmcecosse]

The oil is part of the 'fine tuning' (you can also try a different spring) - Works Rally Minis used EP90 to stop the pistons dancing up and down on rough stages. My TR7 was much improved by using 20/50 engine oil - but this may have been because I ran it quite weak to make sure it passed the MOT emissions without any hassles - and for best economy.

[vibrodolly]

Carburettor much happier - thank you.
The rest of the engine is not. Will write another post.