View Full Version : Stromberg Carb Problem

09-01-2006, 01:46 PM
Hi All, Have a problem with the rear Stromberg on my TR4. It's leaking gas from the vent hole for the air cleaner. By this I mean the holes immediately above the bolt holes for the air cleaner. When throttle is increased gas is sucked back into carb and no leaking. Have played with both the needle and float setting but can't seem to get rid of this problem. Any ideas? Thanks, Mike

63 TR4 Surrey Top
71 MGB OD & Wires

09-01-2006, 02:36 PM
I would be very leary of driving the car until it is fixed. I had a problem years ago that threw gas into the aircleaner and a backfire through the carbs caused a fire. A few anxious minutes followed.
Have you looked at the jet? Maybe a piece of dirt or something is not allowing it to close properly.

09-01-2006, 02:42 PM
It sounds like your float valve is stuck open. Either there is a hole in your float or the valve is bad. Not a hard fix just replace bad parts.

09-01-2006, 06:13 PM
Certainly sounds like a fuel level problem in the carb, it should be running VERY rich if it is too high, check the plugs for black sooty coatings.

09-01-2006, 07:34 PM
I agree, it's more likely the needle and seat and as you can't see what's inside of the Stromberg I would change it and the other one too. Groose jets work fine, just be sure to clean them in paint thinner or some carb cleaner before installing as they come with some kind of lub on them and work after a while when enough gas runs through to wash them off, in the mean time it leaks like crazy. Wayne

09-02-2006, 08:40 AM
Almost 100% certain its the valve. I had the same problem on my rear carb as well on my TR4. The fact that you have already pulled the carb and adjusted the float, I think replacing the needle valve would be a good thing to do.

On my carb, it turned out that the previous owner had put the carb back together incorrectly - the pivot rod holding the float was installed backwards, allowing it to back out which jambed the float - no float, no valve and gas would fly out of the vent. Very dangerous, but doesn't sound like it is exactly your problem!

Since you didn't mention any problem with the float itself, I assume it looks to be in pretty good shape?