Guest Technical Article:

Rebuilding a Weber 40/44/48 IDF

using Redlines kit (92.3240.05)

by Neil Harman

The kit arrives with an assortment of ‘O’ rings, two accelerator pump diaphragms, and a mix of fiber gaskets, none of which will probably be the same as the one you remove! The ‘O’ rings and diaphragm are fairly obvious  where they go,  but In the Redline diagram below, note item 6 – the main gasket.

‘O’ rings are items 23, other parts are items 11 ( Needle and seat gasket) and 54 ( Accelerator pump feed)

If you look carefully, you will see item 6 resembles the first gasket below –

But the part in the kit is like this :

Do not attempt to cut it to match, it would work – these are the steps to use the gasket as it is –

1. As part of the rebuild kit you get a new needle for the float assembly. Go ahead and push out the brass pin holding the float assembly ( 52 in the diagram) , and remove completely.

2. The instructions tell you to set the float to 11mm with the metal assembly C vertical, and the float – this is without the gasket in place. You can do this, but it will require you to disassemble the float assembly again to install the gasket, and reinsert the pin
   OR – and much easier -
   Put the correct gasket on now, and set the float to 10mm from the gasket – the gasket is 1mm thick.

3. You must remove the extended valve holder (50 in diagram) before you install the top plate with the gasket, it will not go on if you don’t. Place the plateon top of the main body, drop in the valve holder extensions and screw them in slightly, secure the top with screws (55) and tighten down the holders (50)

Good luck with your rebuild – don’t forget Weber fuel pressure must be 3psi maximum, or the carbs will flood as soon as you turn on the supply.