carburetor settings.

whiterover

Member
Hi everyone. Yesterday I reset the mixture on my 2200 using colortune, where the instructions say that the flame should be bunsen blue, having achieved that and with both carbs sucking evenly, idleing between 800 & 900 nicely, I took the car for a drive and the mixture seemed lean (coughing, spitting etc) eventually with lots of small adjustments Rover became driveable with the flame on yellow.
Am I getting this correct.

John.
 
Hi John,

I've always found the colourtunes tend to do that with SU equipped cars for some reason. I know a lot of folks on here swear by them, but I've never felt that confident. Added to that, modern fuels burn differently compared to the stuff the carbs were setup for. I've found most need to run a little rich compared to original settings. Sounds like you've got it right.

Best,

Steven
 
I'll be borrowing a colourtune later on this week to check my settings after overhauling the Twin SUs on my '69 2000. From what I've read the flame colour has to be bunsen blue with some yellow . The performance is fine but I shall taking her for a trip overseas and definitely don't want a weak mixture. Most probably I will have 2 colourtune plugs and I was going to fit one in the number 1 and another in number 4. Any thoughts?

regards
Richard
 
I had colotunes in the past and also a portable CO analyser, but after all those years i prefer setting the mixture by "feeling" the engine. The only instrument that i use is a vernier caliper to make sure that both needles are exactly in the same position within the pistons, and the top of the jets are on the same height realtive to the carb bridge. Mind you, this works for new / unworn needles and jets, and obviously matched carbs.
 
I'm with Demetris, best way to tune is by feel. A wideband sensor in the down pipe is a good way to go if you have the time, money inclination. A friend has done it on his 66 cooper S. But you'll drive yourself crazy watching the gauge.
 
I had colotunes in the past and also a portable CO analyser, but after all those years i prefer setting the mixture by "feeling" the engine. The only instrument that i use is a vernier caliper to make sure that both needles are exactly in the same position within the pistons, and the top of the jets are on the same height realtive to the carb bridge. Mind you, this works for new / unworn needles and jets, and obviously matched carbs.
Ah Demetris, great minds think alike!! That is exactly how I set the carburetors with vernier and all . I will be using the colour tune to check how close I am.
 
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