Very little help, but a start.
Martin's metering block replaces the electric valve that admits air to lean the carb - at the rear pointing to the firewall. I can't post pics that would make it clear, but here is the original description:
Martin's 2.8 Metering Block
How it works;
The large oval hole is where the air enters, air is taken from top of the carb
The larger of the round holes is the high speed bleed.
The small round hole is the idle bleed.
When the screws are screwed in to completely cover the holes it causes a full rich condition and when the holes are open the mixture is full lean.
For tuning, the best place to start is to adjust the screws to full rich, warm up the motor and then start to lean it out gradually until you find a setting you like. you can use output from the o2sensor to make the adjustments if you like.
how it's made;
find a piece of 1/2" thick material, nylon, teflon a piece of very dense wood would probably work.
remove the mixture solenoid from the carb and cut a piece of material the same shape and size. You can use the gasket as a pattern. Then procede to drill the holes. if you use the photo's and the gasket as a guide it should be self explanetary. The large screw is 1/4" x 20, the small screw is 10-24. If you look on the photo's you will see I have put rubber tubing on the screws to prevent them from vibrating loose.
let me know what you think.
take care.
Martin.
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