I've suspected for some time, since I did my first Z-Therapy taught carb tune, that I was running too rich. Excessive exhaust, bad mileage, and finally, black plugs with wet plug holes. So apparently, I need to lean my mix up.

How do I go about this? Do I go through the entire procedure of backing out the idle pins and resetting the mix nuts, or can I just go straight to the mix nuts?

Also, the part that confused me the most the first time I did my carbs, was the direction I was supposed to be turning the mix nuts. The engine service manual procedure says, "Idling fuel flow volume is reduced by tightening the idling adjusting nut (turning it to the right), and is increased by loosening the idling adjusting nut (turning it to the left)." I know that this sounds completely stupid, but it was the tightening and loosening part that confused me. What I understood it to mean was that turning the nut to the right (looking down on the carb - i.e. clockwise), leans your mix. Did I get that right?

So if I want to lean my mix can I just drop my nuts ( sorry couldn't resist)? How much? Or should I redo the entire carb tune?

um, from the last time i adjusted my carbs, i seem to remember that turning them COUNTERclockwise (when looking down on the carbs) leans the mixture. of course, i had very little sleep last night, so....

"Dropping" the mixture nut will richen up the mixture. To lean the mixture you need to screw your nut (, ) into the carb body.

Looking at the carb from the top, turn the nut counter-clockwise. Looking at the carb from the bottom, turn the nut clockwise.

Ok see I did have it wrong. You turn it to the right to tighten, but that's from looking at the nut (i.e. from the bottom of the carb). Got it. That makes much better sense.

Ok so that means my mix nuts are out too far, making my mix too rich. So can I just tighten them, or do I have to reset the throttle screws and check my flows again?

Seems to be a whole lot of screwing going on here. !!

I think it might be best to go through the whole procedure again. One adjustment affects the other so to get everything right it probably would be better to start from scratch. Might be part of your backfiring problem too.

Just don't "screw it up".

OMG, all this innuendo and puns...driving ..me..nuts..

What do you expect from a bunch of Z "car nuts"????:tapemouth

It is worth taking it to a garage with a exhaust sniffer as it may be running rich down low like mine but leans out at higher revs.

To get the right mixture at 3000rpm I have to run it rich at idle.

Still have to diagnose why...............

Cheers

Glenn