Help lean out my Demon :)

[stang387]

I have your basic mustang setup and no matter what i do it runs rich when cruising and a little worse at WOT.

306 DSS
Compression 9.5
650 Mighty Demon recalibrated down to a 575
Victor Jr. intake
AFR 185's Not ported but fully polished
Z-303 camshaft
1 5/8 long tube headers
2 1/2 exhaust
MSD distributor / coil and 6AL
Experimenting with timing (15-20 at idle)

My LC-1 Innovate setup reads a very steady 10.8 to 11.2 cruising at
55 mph.
WOT it goes as low as 9.8 and stays mid 10's.
Primary jets are down to 67.
Secondary jets i have slowly brought down to 69.
There are no power valves in Mighty Demon on the secondaries.

When i first got the carb it had a stumble just off idle or when slighty increasing speed when cruising. I put the squirters off my holley on and it cleaned it up. The squirters were .004 bigger than the stock Demons.

The plugs are VERY white after 3 weeks of tuning with the above mentioned A/F readings.

Fuel pressure is between 6 to 7 p.s.i.
Floats are just below 1/2 in the site glass.

It runs good but it seems doggy.


Any ideas??

 

[Rick James]

Did you adjust the idle mixture using a vacuam gauge?the float level is supposed to just barely trickle fuel out the bottom of the hole.I guess you have the clear plugs?

 

[stang387]

I adjusted the 4 mixtures screws using the wideband o2 sensor.
It's fine at idle.

 

[Rick James]

Did you adjust the floats yet?I am a little concerned about the plugs being white .I am no carb expert just trying to help with what little carb experience i have.

 

[stang387]

Yup the floats are just below half in the site glass.
Im not to worried about the plugs.
The Only time it goes lean is when im cruising and barely increase speed.
When i do this is goes lean for a second or two then it cleans up to 10.8-11.2
on A/F.