Best way to do it, is to buy an air/fuel ratio gauge. yes it WILL run richer but you have to increase the fuel supply to accomodate the air increase. You WILL have to increase the fuel supply going into the carb if your running any kind of induction kit on such an engine. otherwise you'll be running around with the choke on constantly which isnt good. fit the air/fuel ratio gauge then just play with the carb fuel pin untill its setup to use the choke. you just have to adjust it, try it. adjust it, try it etc chap. Its the ecu's job on a fuel injection engine to richen the mix automatically or lean it, because you havent got a learning emission control ecu you will have to do it instead. hope that helps matey. Try ebay for a gauge and the vacum pipe/tpiece you'll need, failing that.. demontweeks sell cheapish ones with all the accessorys you need.