Flooding

Post by **poppet** » Mon Nov 10, 2008 8:37 pm

Hi
I have a HS4 SU carb fitted to a marina engine in a moggie. The float chamber keeps flooding through the air hole. Ive done all the usual things - made sure the float is ok, cleaned and re-placed needle, needle seating and pivot pin etc.
Any ideas please?
Steve

Post by **mike.perry** » Mon Nov 10, 2008 9:22 pm

Have you checked that the float is the correct height to close the needle valve? The settings appear to depend on what sort of needle valve you have. I'm just reading this from the SU Manual.

Post by **rayofleamington** » Mon Nov 10, 2008 9:36 pm

float level setting as mentioned already.
Also have you checked that the needle and seat actually seal? You can do this with the carb dissasembled* - light pressure on the needle (with your finger) should stop the flow of petrol.

* Health and safety warning - make sure you're not smoking, the petrol doesn't go anywhere, you are wearing barrier cream to protect your hands, wearing well fitting goggles, safety boots in case the car rolls over your foot, newspaper spread around in case any petrol does spill, a safe method is required to dispose of your petrol soaked newspaper (have another bonfire) and make sure you have completed a full risk assesment ;-)

Post by **Onne** » Mon Nov 10, 2008 11:13 pm

And have time for a cup of tea first...

Post by **RogerRust** » Tue Nov 11, 2008 5:45 am

A common problem with the HS4 is not having the float chamber level. It will leak unless it is.

Post by **bmcecosse** » Tue Nov 11, 2008 10:44 am

Absolutely - it must be VERTICAL (I think this is what RR means) - if it's lying at an angle then it will always flood. This is one major advantage the HIF SU has - it can (within reason) be mounted at any level and it will work! And for the same reason it doesn't surge on corners either.
HIF = Horizontal Integral Float