Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - float valve ??

Hi after changing my jet bearing seals , having problems tuning. Sometimes it runs really rich, took out the piston , fuel simply sprayed out the top of the jet, indicating float valve open. Other times when I open the throttle on that carb, simply dies indicating lack of fuel, I m ordering a new float valve although the one in is new. Fuel looks clean, should I look at fuel pressure, fuel pump. At idle I had hear the pump tick about once a second , is this normal ?
Driving me to distraction at the moment -HELP !!
D J Joy

Or is it worth fitting Gross Jets?
D J Joy


Some people swear by grose jets. However, in recent times there have been problems with some batches. I run original valves and have no problems with them.

First tell us what pump you are running. Fuel pressure can be a problem with some aftermarket pumps, but not the standard MGA pump.

Steve Gyles

If you have the SU valves AUD 9095/6, plastic cruciform with a spring loaded tip, I've found some with flash along the edges of the plastic. This causes erratic operation; a few seconds with fine abrasive or a nail file fixes. I have no use for Gross Jets.

FR Millmore

Float punctured?
Art Pearse

I have had grose jets installed in my carbs about five years ago, and I have never experienced any problems with them. When I had the original style float needles, even when new ones were installed, I had a few problems at times with fuel leaking out of the overflow pipes. Some people don't fancy grose jets for reasons known to them. The other excellent alternative is to use viton tipped needles which may be obtained from Basil Adams.

F Camilleri

Gross jets here for more than 20 years, 200,000+ miles, never any problem. But you do have to keep the fuel clean. DO not buy "Gross Type Jets". They are not the real thing, but are low quality knockoffs with known problems.
Barney Gaylord

This thread was discussed between 12/02/2013 and 13/02/2013

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.