i just tuned the carbs up and synced them and it idles great now and pulls hard through the whole rpm range. i adjusted the idle mixture screws evenly by the book and per instructions how to set them and now i have some slight muffled backfiring out the tailpipe when downshifting. it isnt bad, but it didnt do that before so im thinking im a little too lean maybe? or would it be a little too rich?
the idle mixture screws are out 2 turns right now for 80 degrees temperature outside for the SU carbs.
i had them both at 1-3/4 turn out and thought i might be a bit lean as most of the books say they should never be less that about 1-3/4 turns out but ill turn em to 1-1/2 out and see what that does. i know when the choke is on in the mornings its way too rich and i cant even use it once the engine fires. whats weird is i turned them in from their original settings 1/2 turn when i tuned the carbs.
i also heard tho z therapy carbs are pretty much set for 280 motors wanting more fuel and i will be really rich from the get go jetwise. i would just hate to go too lean and hurt the engine.
i also unhooked my throttle dampner vacuum thingamajiggy thats on the balance tube that slows the throttle down when letting off the gas (emissions). that probably makes it a little worse having the throttle slam shut now when letting off the gas.