[Mouse]

I have been told my Sierra is running to lean, Is this a easy thing to
Adjust? If so how do I do it
Thanks
James

[DMAC]

Running lean when?

If at idle you can adjust the idle mixture screw, but this is factory set and should be good. Its also difficult to get to.

If its under normal operating revs the only way to adjust it is via the changing the jets. These are found in the fuel bowl.

How did you measure the fuel mixture to know its lean?

[Mouse]

I havnt adjusted anything, just got it back from getting a couple of things fixed and was told it was running lean by the mech

[Jackson]

Did he say why he thinks it is running lean?

It could be that your float is set wrong, needle and seat has some gunk on it, tiny bit of crap in a jet, little air leak somewhere.

[Mouse]

It's back firing we have put a new dizzy in and the timing has been done seems to lose power about 90k in 4th and won't go above 100 on flat road
It has 30in muddies and trailtough gears done it also doesnt want to rev past about 4.5k

[Jackson]

I would check the fuel filter isn't full of crap, then that the pump is still pumping all right, then spray carby cleaner around the base of the carb to see if there is any little air leaks, then spray carby cleaner in your carb with the motor running, then see if you can spray it in the jets and needle and seat.