Hi everyone,

My stock dual solex carbs were running great (2L kombi). Until a needle valve stuck on the right side and petrol started leaking out all over the manifolds and plugs (scary).

So I replaced the needle valve. It's a job so easy that even I could do it. But now the bus runs really rough. What could I have stuffed up?

TIA!

Float level?

Did you fit the air cleaner horn back onto the top of the carb correctly? Is everything else on the air cleaner connected up?

Did you accidentally pull any wires off the carb?

Is the cross-linkage still connected properly? It is spring-loaded, and it's easy for the little plastic cup on the right-hand ball to go missing in the depths of your engine bay. Check there's no slop in the linkage.

Did you remember the gasket between the top and bottom of the carb??!!

Thanks. I put in a new gasket, I'll check the other things.

Is the float level difficult to check?

Don't want to offend, but it sounds a little like your original problem was a leaking float.

Bugger!

Well here's some more detail on the original problem: I noticed petrol leaking out of the right carbie. It was dripping off the throttle lever (where the linkage from the cross-bar clips on) and running down the inlet manifold, making puddles on the tin and dripping onto the road. The petrol was only below the flange, not above it. I told my local mechanic what was happening and he straight away said it was a stuck needle valve and gave me a new needle valve and gasket (he didn't charge me, I'm a regular and he's a nice guy). Now that I've replaced the needle valve there's no petrol leaking at all, it's nice and dry.

So could those symptoms be caused by a leaking float? And could a still-leaking float be causing the rough running without any external leaking?

If it's not leaking now, it may be the float's OK, or the new valve may be stuck in some way, or you may not have the float level corrct. Best to pull the top off the carby and check the level - my Bentley says the fuel should come t0 19.5mm from the top of the carb body (+or- 1mm,) but this is on a single.

Dual carb float level is 12 to 14 mm from the top according to Bentley.