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In addition to the comments above...
The HD6s also require the throttles to be completely closed and use the idle screw. They are essentially the same as HD8s but smaller.
Once the car is tuned, it's useful to pull the domes and use a dial caliper to check the jet drop on each carb and equalize them. For instance if one is down .055 and the other is .045, change both to .050. Barely noticable turns of the mixture screw can make big differences in the mixture. We're not talking quarter turns here, but the thickness of the screwdriver blade. Clockwise is richer.
I used to use two colortunes to get in the ballpark on the mixture but Healeys don't seem to run right unless "colortuned" on the rich end of the scale. Now I use two K&N oxygen sensors, but that's another story.
Make sure the choke linkage returns the jets fully home. On the older cars, the choke link-rod between the two jets can have the effect of keeping one of the jets down when the other is fully seated.
The acceleration system is a combination of the weight of the damper oil with the tension of the big spring inside the dome. My friend's HD6 car had the weakest spring and we tried first the mid-range spring, then the stiffest, then settled back on the middle one. The difference in driving with the middle spring is noticable over the light one. These 3 springs are listed in Moss.
The HD6s also require the throttles to be completely closed and use the idle screw. They are essentially the same as HD8s but smaller.
Once the car is tuned, it's useful to pull the domes and use a dial caliper to check the jet drop on each carb and equalize them. For instance if one is down .055 and the other is .045, change both to .050. Barely noticable turns of the mixture screw can make big differences in the mixture. We're not talking quarter turns here, but the thickness of the screwdriver blade. Clockwise is richer.
I used to use two colortunes to get in the ballpark on the mixture but Healeys don't seem to run right unless "colortuned" on the rich end of the scale. Now I use two K&N oxygen sensors, but that's another story.
Make sure the choke linkage returns the jets fully home. On the older cars, the choke link-rod between the two jets can have the effect of keeping one of the jets down when the other is fully seated.
The acceleration system is a combination of the weight of the damper oil with the tension of the big spring inside the dome. My friend's HD6 car had the weakest spring and we tried first the mid-range spring, then the stiffest, then settled back on the middle one. The difference in driving with the middle spring is noticable over the light one. These 3 springs are listed in Moss.
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