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MG TD TF 1500 - Another H4 SU moment

I have pulled 4 carbs apart and have found another deviation that makes me uncertain about proper assembly. This is in regards to the brass cups the secure the cork jet seals with a spring pressing against the cups. Do the cups face away from the spring and engage the seals or do they face away from the seals and engage the spring? When I took my various carbs apart they had different orientations which lead to the question.

Also I noted that the cork seals that were removed were shrunken and though not certain, may have been allowing fuel to circumvent the jet and flood the carb from another source to draw fuel from. IDK but it seems plausible> Your thoughts?

Cheers

Bill Chasser jr
TD4834
W. A. Chasser Jr

The seals are on the concave side of the cup. The spring abuts the flat side of the cup.
readlist

Bill, the cork seals must be soaked in oil, overnight should do it. I soaked mine for a couple days. And yes the concave part of the washer goes on the cork. After trying the O rings, which grabbed the jets too tight, then going to Teflon, which leaked like a sieve, I went to cork. The jets do not leak and they work very freely, actually returning to the closed position on their own, no forcing. Engine runs like a dream, idles at 600 RPMs and no shake.PJ
Paul S Jennings


Bill ,
If it helps.
Here is the way you install them for the correct seal.


R. D. Jones

Thanks everyone. I have them now installed with the cup side to the corks. Had the spring not fit into the cup when inverted the question would have been self evident. The carbs are now back together. Jets centered and set .070 below the bridge. Needles are set at a consistent 1.531 from the piston face. Floats set at 7/16ths. Idle screws backed off and set 1/2 turn from closed. I still have two issues. 1) After playing with all of my pistons and covers, I could only get one to drop at 5 seconds, one at 3 and two at 3.5 seconds. I elected to put the matched pair in place at the moment so at least I have a set that are balanced. 2) the float bowl mounting bolts where switched back to the banjo style bolt instead of the double hex arrangement of the MGA carbs that I had. Unfortunately the banjo bolt is slightly longer and the Moss washer set for the MK II/TF configuration are too shallow to allow the bolt to snug the bowl. So I cleaned up the rubber isolaters and looked them over for cracks, tears and found none. They are still plyable so I reinstalled them with the thinner one on top the thicker seal on the bottom the concave washer facing cup side down to the bolt.
W. A. Chasser Jr

Bill, what needles did you decide on?
Len Fanelli

Len At the moment I still have the GJs in place. I have ESs and 6s which I'm told are both fatter. The 6s are std MGA 1600 and the ESs are of course std TD H2s. I was closer to having the carbs idle but when the bowl mounts started drooling I was done. I'm pretty sure it was a float level issue but couldn't pull the dampers and drop the jet to measure the levels. It'll be a while before I can make another effort at tuning as the tank has been pulled and the tub prepped for another go at paint.

Cheers

Bill Chasser jr
TD4834
W. A. Chasser Jr

This thread was discussed between 16/05/2015 and 17/05/2015

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