Hello.
Two H6 carbs have been fitted on my BN1 by the previous owner (I don't think that camshaft nor pistons have been modified the same way as a 100M).
Incidentally, last week I noticed that the accel. linkage fitting was wrong, the angle between the link and the lever actuating the throttles preventing them to open fully (brilliant job done when replacing carbs seals by famous and very expensive Healey "specialists" here, boasting of racing @ Le Mans Classic. What a pity...).
Having solved this issue - and obviously got a better performance - even if the car seems to operate correctly (starting, idling, ride), I decided to check the whole tuning (just in case !), including sync, mixture...
So I have a question regarding mixture check : following the SU instructions, I push the small pins to slightly move the carbs pistons up, and always get decreasing rpm.
This should indicate a too weak mixture, BUT : working on the front carb (didn't try with the rear one), I already unscrewed the jet adjusting nut by 3 3/4 turns, and the engine keeps stalling when the piston is lifted...
As there seems to be not so many threads left on the jet bearing for further enrichment, I'm afraid that I missed something : any idea ?
Another hypothesis would be that the previous owner threw the carbs without thinking about their tuning, and the needle and / or the jet don't match the right setting for this engine. If so, what should be the right needle/jet needle combination ? I guess it should be similar to a 100M one, but couldn't find the information.
Thank you in advance for your help.
Matt
Two H6 carbs have been fitted on my BN1 by the previous owner (I don't think that camshaft nor pistons have been modified the same way as a 100M).
Incidentally, last week I noticed that the accel. linkage fitting was wrong, the angle between the link and the lever actuating the throttles preventing them to open fully (brilliant job done when replacing carbs seals by famous and very expensive Healey "specialists" here, boasting of racing @ Le Mans Classic. What a pity...).
Having solved this issue - and obviously got a better performance - even if the car seems to operate correctly (starting, idling, ride), I decided to check the whole tuning (just in case !), including sync, mixture...
So I have a question regarding mixture check : following the SU instructions, I push the small pins to slightly move the carbs pistons up, and always get decreasing rpm.
This should indicate a too weak mixture, BUT : working on the front carb (didn't try with the rear one), I already unscrewed the jet adjusting nut by 3 3/4 turns, and the engine keeps stalling when the piston is lifted...
As there seems to be not so many threads left on the jet bearing for further enrichment, I'm afraid that I missed something : any idea ?
Another hypothesis would be that the previous owner threw the carbs without thinking about their tuning, and the needle and / or the jet don't match the right setting for this engine. If so, what should be the right needle/jet needle combination ? I guess it should be similar to a 100M one, but couldn't find the information.
Thank you in advance for your help.
Matt
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