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Triumph TR6 - SU HS6 needle

Repaired both SU, new jets, needles, throttle shafts, floats, etc. The problem that I have is at idle. It is too rich,have jet adjusting nut all the way in. Need to know the size of the needles as I believe they are too short and therefore both SU run too rich while idling. No problem at high speed once the spark plugs get cleaned.
Angel L. Traverso

Hi Angel

Not sure of your post here but is "in" not increasing fuel flow rich on SU?

Bill
Bill Brayford

Hi Angel
If your SUs mixture is adjusted from underneath you are going the right way, if they are adjusted from a screw on the side you are going the wrong way!!
If you can identify which type of SU you have fitted the Moss catalogue gives A range of suggested needles as a starting point for engines in various stages of tune
If it is a biased jet SU on a standard engine they suggest BDB needles [NZX8002]
Ron
R. Algie

Angel--For a stock TR6, the suggested needles are BAX or BAG.

Good luck.

Rick O.
Rick Orthen

Let me rephrase my problem...have SU HS6 carburators, they are not Zenith-Stromberg like the originals. The mixture is adjusted from the bottom, clockwise adjustment is closing the jet...less fuel. What I need is the lenght of the needle, have two pairs of needles and they have different lenghts. Hope this clears any misunderstanding...
Angel L. Traverso

Angel-The length of the needle isn't a factor. If you are running too rich with the jet fully up, either the needle is wrong for the jet size, the float level is incorrect, or the needle valve is jammed open. As a starting point, raise the jet until it is even with the bridge, then lower it 2 turns. First check the identity of the needle. The ones Rick suggested will work for the TR6,there are also others. Also, make sure the jet is centered so that it isn't touching the needle, unless the spring loaded type needle is used.
Berry

Hi Angel
Do you have the needles mounted correctly? ie the shoulder of the needle flush with the bottom of the mounting if they are too far in your mixture will be too rich particularly at tickover. You do not state whether you have fixed or spring loaded type needles as the needles for each type are not interchangeable.
Could you give us some history of the conversion ie have you recently bought the car or did you do the conversion
Ron
R. Algie

Hi everyone and thanks for the inputs. The needles are fixed one.Have the British Toy for about 2 years, PO had different size needles, one of them have "TW" stamped on it, the other is washed out . One is 2.030" overall lenght and the other is 2.080". Right now carbs have needles with a "414" stamped and equal lenghts, 1.968". My caliper is not state of the art, it could be 3/1000 off...!!! E-mailed this info to Moss, they are checking out. Any other tips from you guys will be greatly appreciated, not in ahurry to drive my Toy.. it is 94F outside...!!!
Angel L. Traverso

This thread was discussed between 22/07/2003 and 24/07/2003

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