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MG TD TF 1500 - Sootey exhaust

The adventure continues....Ok, I am running my XPAG set were I got it from the PDO. I've replaced the head
and had the carbs to the local shop. The car was timed dynamically with 7 degree retarded spark. It starts and runs " OK " but gas milage is poor and the exhaust is sooty. Should I try turning the jet adjustment nut up a flat or two? I fouled a plug after 250 miles. Oh yeah, carb floats seem to be at the same level for both. Tom
Thomas McNamara

Oh yeah, I forgot to say that when testing for spark that it seemed " weak " compared to a modern car. Is this correct? Tom
Thomas McNamara

Thomas - Yes you need to run the jets up, probably several flats and get the timed to at least 7° advanced, perhaps even more than that for best results. The spark will probable seem week compared to modern cars since the voltage is considerably less. Good luck - Dave
David DuBois

We have a 54 TF 1250 that has a tendency to run a little sooty and will foul the plugs if left to idle too long.
I use Champion 123RN5C plugs which seem to be cooler than the original Champion NA8. (no longer available)
However, I have found that under some 3500-4000 rpm extended running the plugs indicate the correct color condition. If I put back the NA8 plugs the low idle fouling goes away.
Anyone have a better suggestion on plugs, I am willing to try.
colin stafford

It seemed that no matter what I did to the carb and fuel system my 50 TD kept running so rich that plugs fouled when just idling. After carb rebuilds and adjusting the jet nuts up and down numerous times with no improvement, I nearly gave up until I decided to take the chamber floats out and sure enough they were heavy with fuel. Replaced them, re-set jets and car runs great with no fouling. Incidentally, I also found a tilted air filter chamber which was obstructing air flow due to the increased depth of filter oil. If this has nothing to do with your problem, please reserve for a possible future aggrevation

Thanks,

edtdbrit@aol
Eddie W. Haynes

Hello. Things that make a TD run rich: Air cleaner- if orig. oil bath- check for crushed down top and/or bent "legs" that hold the top part off of the bottom. Take the cleaner/manifold off and drive and see if trouble disapears.
Carbs: Incorrect float level, float problem (as mentioned above), wrong dampers (TD carbs must have dampers with a small hole in it), vent hole in damper plugged by previous owner, wrong jet, wrong needle (easy to do- I ordered a pair of MkII jets in error and those do run really rich!), some of the o-ring type jet seals turn to mush and leak- replace with the old-fashioned cork, incorrect assembly of jet bearing, leaving out parts (such as the top jet bearing sealing washer which is too thick and will not work with some new carb kits).
Plugs: early or late TD? TF or late TD plugs are 3/4, early about 1/2 reach. Gotta know which one to use. Have always had the best luck with NGK B6HS in my early TD (These have new part # now). These also used to be used in a lot of 2 stroke dirt bikes (late 70s), so they do fire well in oil. Even running really rich shouldn't foul a plug- what about oil? Change/check the points, cond., coil, wires- really easy for a wire end to pull out of the brass washer and totally fry. Good luck!
George Butz

Tom, I'd suspect the coil...my car was bewitched with a weak and intermittent coil. Had similar symtoms...like fuel starvation. These origional coils are perhaps approaching 50 yrs in age and are of an old oil filled design!
Steve Tobias

Thanks for all of the ideas, it looks as if I have a jet/needle problem with at least one carb. The local shop did not seem as knowledgeable as some others. I guess I try sending them out through the mail and see what happens.
Thomas McNamara

There was someone else a few months ago who had that problem - namely, running too rich - and I told him to get EW needles instead or the standard ones - whatever they are. He wrote that solved his problem. It solved mine a few years ago.

Denis
Denis L. Baggi

This thread was discussed between 20/06/2000 and 03/07/2000

MG TD TF 1500 index

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