TR6 How to adjust idle mixture on TR6

[Slider748]

Can the idle mixture be adjusted without using the Triumph special tool?

 

[Paul Johnson]

No. Well, I suppose one could take the carb down, make a slight turn, put it back together and check the results, but really, no.

 

[Rick O.]

Yes you can, but you risk tearing the rubber diaphram that seals the piston air space. Get a long T-handled hex wrench (forget the size) and grab the piston with your fingers to prevent it from rotating as you turn the hex. Do not grab the piston with pliers as you will score the smooth surface and ruin the carb. A good initial setting is 2 turns CCW (left) after reaching full CW (right) lock. Remember, turn "right for rich" and "left for lean."

 

[Rick O.]

Neglected to mention that you first have to remove the four screws holding the carb top and remove the top. You are certainly better off buying the tool as it will be used often.

 

[piman]

Hello Rick,
there is something wrong if you continually have to adjust the mixture, almost never is how it should be.

Alec

 

[Rick O.]

[ QUOTE ]
there is something wrong if you continually have to adjust the mixture

[/ QUOTE ]
I agree with your assessment Alec. But there are some of us who dial-in the mixture in quarter (or less) turn increments and read the plugs/measure exhaust oxygen content in the pursuit of the perfect mixture compromise. In these instances, the special tool is invaluable. The piston lift test is not always the best way to set proper mixture. Just a different angle on the ownership experience.

 

[piman]

Hello Rick,
I agree about the pin lift, and I prefer using colourtune plugs as a main guide. Do you do an oxygen test on load, i.e. under driving conditions?

Alec

 

[Rick O.]

Yup, under load. The readout is in the cockpit. Before Nelson Reidel recently pulled the tech articles from the Buckeye Triumphs website, there was an excellent how-to on the exhaust gas analyzer setup. If you are really fanatical, you can shave needle profiles to suit your goals too.

 

[piman]

Hello Rick,
I am running a fuel injection set up on my Triumph, I just play with S.U.'s on my wife's Morris 1000.

Alec

 

[Slider748]

Great help. I ordered the special tool as it's probably the best way to go for a rookie.

 

[Slider748]

I got the special tool today and made some adjustments. Then out of curiousity, I took the top off the carbs to see how it all works. Now this thread makes more sense to me. Thanks a lot. I didn't realize the amount of adjustment was so small - about 3 turns.