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Triumph TR6 - Idling inconsistently

I recently changed the oil from 10W30 to 20W50. I also added EOS (engine oil supplement) and lead to the fuel. All a first for my TR6.

Now the engine idles inconsistently and will occasionally stall. There is also some gurgling when decelerating.

Do the carbs need to be adjusted after making the above changes or is this a coincidence?

John, you said..."I recently changed the oil from 10W30 to 20W50. I also added EOS (engine oil supplement) and lead to the fuel." The change to 20w50 is the right thing to do, however EOS is an OIL supplement and should be added to the oil when doing an oil change. If indeed you added EOS to the FUEL, that would most likely cause your engine to stall. I would suggest you drain out the fuel(I don't know what to suggest for disposal) and refuel with fresh . Then add EOS to your 20w50 oil.


Pete Russell

Sorry guys, I worded incorrectly. I added EOS to the oil, NOT the fuel. I added only lead to the fuel.


Adding lead to the fuel may change it's combustion properties and quite possibly the carb fuel mixture may need to be readjusted. Lead depresses the volatility of the fuel

Changing the oil and adding EOS to it I don't think will have any effect on the idling properties of the car.

Michael Petryschuk

John, you say you are adding "lead" to the fuel. In the old days of leaded fuel it was actually tetra ethyl lead, which did a few things to the fuel. One was it increased octane of the fuel depending on the dosage, and provided an "anti knock" as well as being favourable to the valve seats. So not sure what this "lead" is but as Michael says it may be changing the properties of the fuel. I would also check the timing.

Pete Russell

Sometimes we look for something too difficult.

I was removing a spark plug to check for colour, when I noticed one of the emission hoses off of one carb. Problem corrected.


This thread was discussed between 09/07/2009 and 11/07/2009

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