MGB Register Forum

I am in the process of refurbishing twin SU carbs for my B.
The floats are the all plastic type and need adjusting as they don't meet the 1/8 inch requirement. I have changed the needle seat ont he one on the right in the picture (picture loaded upside down, sorry), it used to drop right to the bowld lid, so that made a bit of improvement. I am aware that this type of float can't be adjusted unless you put washers beneath the needle which apparently is a great faf.
This got me thinking, would it be possible to adjust the needle housing height by inserting washers underneath it before screwing it back on the lid to make the whole unit rise, therefore rising the float height. Would this impair on the proper working of the needle and float?
Or, do i buy new floats with the metal fixing and swap them?

Remy

The HS4 float chambers on my 1972 MGBGT look just like yours. The level is simply adjusted by bending a piece of metal?

Ian F

I upgraded the floats in my '67 BGT to the "stay up" type manufactured by Burlen. They are a closed cell material design which is suitable for ethanol fuels and are very simply adjusted for height by bending the metal tab on top. They have proved to be very reliable over the last 5 years or so. I would recommend using these in any carb refurb.
Part no. is WZX 1304 and are available from most MG parts suppliers.
Geoff.

Ian F wrote: Fri Dec 05, 2025 4:05 pm The HS4 float chambers on my 1972 MGBGT look just like yours. The level is simply adjusted by bending a piece of metal?

Ian F

The floats that I have got are the full plastic ones without the piece of metal to connect them. I believe that they can't be adjusted which is a bit of a pain. I'll probably get new ones.

Geoff Norcliffe wrote: Fri Dec 05, 2025 6:09 pm I upgraded the floats in my '67 BGT to the "stay up" type manufactured by Burlen. They are a closed cell material design which is suitable for ethanol fuels and are very simply adjusted for height by bending the metal tab on top. They have proved to be very reliable over the last 5 years or so. I would recommend using these in any carb refurb.
Part no. is WZX 1304 and are available from most MG parts suppliers.
Geoff.

Thanks for the advice and the part number. I'll order some of these along with the linkage as I am missing these too.