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MG TD TF 1500 - Carb Leak

On a cold start the front carb bowl leaks, gas spurts from the tickler pin in relationship to fuel pump if I tap/jiggle and poick up pin leak spots. Do I simply replace the tickler pin and accompanying spring or is this indication of something else i.e stuck float, worn sleeve of the top cap. Other than this carbs fine don't seem to need overhaul. Leak would be signifcant if I didn't lift bonnet and make ready to jiggle on start
Jon L

Two things that can be wrong are #1 float level too high. Can be caused by leak in float making it too heavy. #2-You have no need to (tickle anything to start if everything else is right.It seems that you could have a leaky float valve. Pull the pistons from both carburettors, turn the key on with the choke in the off position. Look in the hole of the center(jet and the fuel level should be approximatley 1/16 inch down. Make certain that both choke levers are allowing the jets to be pushed in th up position.
Sandy Sanders
Hudson Florida
conrad sanders

Jon - Check your e-mail, I am sending you a fix for another possible problem. In more modern carbureted cars there is an adjustment called float drop. No such an adjustment is called for in our cars, but it should be because it is possible (especially in float bowls with worn float lever pins) for the float lever to drop so far that the needle in the needle valve can become jammed between the sharp angle of the lever, making it impossible for the float to be pushed up to close off the valve. The fix is to cut two slots in the back of the lever to form a tab that can be bent to limit the lever drop such that it can't trap the needle. Some of the float levers already have these slots cut in them.
Cheers,
Dave
David DuBois

As others note, the cause of the fuel bowl overflowing should be found and fixed. Whether new or old, the tickler pins do not seal this location in the fuel bowl lid. In fact, it is recommended that the opening be sealed to prevent fuel from spilling and contacting the hot exhaust manifold below. The result could be disastrous.

I removed the tickler pin assembly from the fuel bowl lid, cut off the top two-thirds of the tickler pin, then bedded the pin in epoxy putty in the fuel bowl lid. The outward appearance is as original and a safety issue has been corrected. See the archives for more information.

Larry
Larry Shoer

The above responses beg the question "Isn't a sticky float the reason there is a tickler pin?" Seems like if they put this on the carb. It must have been a recognised issue.

I agree that the underlying problem needs to be identified and fixed, but these carbs do have overflow tubes on them. Are you plugging these off also?
Bruce Cunha

Before I put an in-line gas filter on years ago, grit/rust/crud would stick in the needle valve, requiring a tap on the pin to flush it out. You have to leave the vent tubes open if you block the tickler pin holes, as well as using the correct notched washers on the chamber bolt.
George Butz

The tickler pin opening and gasoline overflow tubes are in two different locations. It is far more likely that gasoline leaking through the tickler pin opening can contact the hot exhaust manifold than gasoline coming out the overflow tubes, which I have routed to the forward side of the engine control bracket.

A better question may be how did the factory expect the overflow tubes to operate when rising gasoline in the fuel bowl would escape through the tickler pin opening before it reached the entrance to the overflow tube!

I have seen T cars on which the overflow tubes have been clipped short, so that gasolice would be dumped right under or beside the fuel bowl. This is neither authentic nor is it safe.

Larry
Larry Shoer

Jon,

I gotta go with Dave on his suggestion. I did the bent tab solution on my TC and no more overflows.

Another cure might be the installation of Grose Jet float valves. No pointy parts to get stuck on the float lever. That took care of the problem on my TF.

Greg
Greg Van Hook

This thread was discussed between 08/07/2004 and 13/07/2004

MG TD TF 1500 index

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