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Always having problems with sticking float needle valves , any recommendation as what ones may be the best standard SU or aftermarket . Also while carbs are apart is it worth changing the white plastic flats to the black plastic ethanol resistant floats?

When you lift pistons by hand and let them drop you should hear a solid clunk when they hit the bridge. Have you centered the the needles?

Are your float pivot pins straight/worn? Might be worth checking/replacing those if the floats are sticking. I would only use genuine SU as they are made to withstand the modern ethanol fuels.

Always worth upgrading to the ball bearing type Needle valves, they'll never stick again after doing so.

Smiffy wrote: ↑Mon Jan 31, 2022 4:03 pm Always worth upgrading to the ball bearing type Needle valves, they'll never stick again after doing so.

I bought these from Minispares but sent them back as my carbs overflowed. They recommended additional washers but I could not stop the overfilling.

Back in the Day my memory says that the HS2 Float Chamber Gasket had a slot about 1/8 inch wide cut out within half of its gasket thickness.. purpose was to allow air to escape from the fuel chamber to be clear the chamber gasket was still a full circle .. today i only see the HS2 fuel chamber gasket as a full in thickness circle..my issue was in the past i had flooding this was before the days of E Petrol & tried solutions with new needle valves also tried these Ball Valves with new floats & pins & eventually i cut the float chamber gasket to give this air gap & somehow i stopped the Flooding was it solved by my adding my venting air gasket ? i have no idea.. Now i rebuild a set of other twin HS2,s and purchase the new ( Expensive ) Float Chamber Top assembly .. these Chamber Covers come complete with the Float & Valve assembled in the new Top Cover but to note they do not come with the venting type of old school gasket & only available in lets say right hand style of float chamber top .. we will see how this new set up gets on

floormanager wrote: ↑Mon Jan 31, 2022 6:40 pm I bought these from Minispares but sent them back as my carbs overflowed. They recommended additional washers but I could not stop the overfilling.

I've fitted two sets one was a original NOS set picked up at a auto jumble (vortex iirc) and the other a Minispares set and never had any problems after.

Current Burlen/HS-SU spec needles and valve assemblies, new floats and axis pins. Flush out the bowls and assemble. And while you're there, new spec hoses from the feed to the carb pipe and pipe to carb bowls. Time taken on a warm Saturday morning 1 hour (or 2 hours if you try to rush the job). Money well spent.

I simply cannot understand how the carb bowls overflow. As soon as the needle valve rises in the screw-in valve, the (low) pressure build-up will stop the SU pump until pressure drops.....fuel pumps again and so on.

In theory they should never flood , but over the years I have had problems with viton tipped valves sticking open occasionally, so maybe I should use original valves from Burlen .