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MG TD TF 1500 - carb leak from float bowl

Started up the 1950 TD & smelled gas by the time I got to the end of the driveway. Drove back to the garage & opened the hood. A steady stream of gas was coming from the vent hole on the top of the front carb float bowl. (Not from the over flow pipe)Turned the engine off. Tapped on the bowl a few times w/ a hammer handle. Turned the key on & gas still came out. Turned it off & figured I'd fix it later. Now that's it's later, it works fine. Key on, no gas leak. Car starts & runs fine. I'll assume the float stuck & then unstuck itself. But I'm probably wrong! So, how do I fix it? Thanks
Bruce Haynes

Bruce,
Probably was the float valve that got stuck. How old is the valve ??
A new viton tipped valve will most likley solve the problem. I just got two from Abingdon Spares.

Steve
Steve Wincze

UPDATE: Went to check the needle valve. Turned the key on & gas flowed out of the float vent hole. Removed the top of the bowl to check the needle valve tip & shazzam!! A tiny piece of what looked like old gasket material came out w/ the needle valve. It's all back together & no leaks. Which leads me to my next question: what's the purpose of the over flow tube if the gas is going to come out of the vent when the float/needle valve sticks? Am I missing a part or something?
Bruce Haynes

The hole originally had a push-pin, held in with a small cotter pin, that pushed down the float. I've never been quite sure why... Later covers had the hole un-drilled.

I generally fill the holes with JB Weld, and then trust the overflow pipes, which have to be directed properly then.

That Wincze guy is pretty smart...

Tom Lange
MGT Repair
t lange

Bruce, make sure you have the proper special segmented washer between the brass bolt and banjo on the bowl top, if you don't have them together correctly, they won't work properly. Put together as per factory, they work fine. A good idea is also to have the overflow pipes exit down low in front of the engine, not near the exhaust pipes. PJ
Paul161

Search archives for tickler pins. In addition to above comments, make sure the overflow pipe is not plugged up. For appearance sake, you can install the ticker pin assembly and seal with JB weld. George
George Butz

Or fit a leather washer to the tickler pin so that it seals when closed.
Dave H
Dave Hill

Check the needle valve forks carefully. At the end where the spindle fits the fork is split into three sections. Two go below the spindle and the centre one above. The centre one has a kink in it to prevent the fork falling too far down and binding the needle valve. If the kink is not bent properly and the floats allowed to dry out, the fork can drop too far and the valve can stick. It is difficult to describe without a picture but if you look at the fork in the lid of the float chamber you will see what I am referring to.

Jan T
J Targosz

Thanks guys! I appreciate the help.
Bruce Haynes

This thread was discussed between 29/10/2016 and 30/10/2016

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