Dear emmision phobes
Rob asks about adjusting the carburator in an attempt to pass California
emmisions.
I don't know much about spitfires or exactly what model carb you have but I
have successfully adjusted the carbs on my 74 TR6.
The first thing to do (as Motorhead always says) is ensure your other things
are up to snuff. Good cap/rotor/points/condenser/etc. Set timing and Idle
speed. Also double check the float level. You will never set the carbs
right if the float is not set properly.
1) The needle adjustment is a good starting place. You may need to adjust
them up or down but that depends on the emmisions output. Yhe first thing
you will need is a CO meter. Moss sells one for $150 (J.C. Whitney also
sells it for about $120). This meter measures CO only. It does not measure
HC so you have to cross your fingers on this count. The theory is that if
you set the carbs right the HC will be OK.
2) The TR6 has an idle mixture screw on the side. It sounds like your carbs
also have these. These screws let extra air into the mixture. Screwing them
all the way in will enrichen the mixture and raise CO. Back these screws out
gradually until the CO meter reading is satisfactory. If you can't achieve
the desired result this way you will have to adjust the needles.
This is a slow process and much trial and error may be needed until you get
the feel for it. Appearently, there is more Art than Science involved here.
Good luck
Dave Massey
TR6Massey@aol.com
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