running rich? don't know why? un-even air/fuel

[MotoEclipse]

Hey so im 260 miles in my new motor. and i put a narrow band on the O2 just to get an estimate on what its doing. well at full WOT it pegs the gauge on the rich bar. and i start loosing power after about 4500rpms.. then when im driving normally the air/fuel bounces back between lean-rich-lean-rich. about 60 times a minute. and i can feel the car surge when the gauge hits lean.... the only "upgrade" i did to this motor during the rebuild was 2G 8.5comp. ratio pistons. do you think that would throw the air/fuel off that much?

i read all the "running rich" threads and really coundn't find an answer.

(my 02 sensor is brand new)

 

[standard235]

Buy a wideband. You described normal narrowband operation

 

[gofer]

Your basing your A/F ratios off of what, a narrowband o2 sensor gauge I'm assuming? That narrowband gauge is what Honda guys use to flag down chicks they're trying to impress with the light show thats going on while they're driving, you can't use it for anything else. Get a WB and you can see what your ACTUAL AFR's are while your driving and while your at WOT...

The o2 sensor is supposed to cycle back and fourth from rich to lean while your at idle/cruise conditions. That means the front o2 sensor is doing its job, keeping your AFR's at a stoich 14.7:1 mixture.

 

[MotoEclipse]

ok. well its going to be awhile for me to get WB bc all my money went into the build.. the car did burn almost a whole tank of gas in 150 miles though...

do u think loading up on itsself would have to do with the lose of power after 4500rpms?

 

[theslab]

That narrowband gauge is what Honda guys use to flag down chicks they're trying to impress with the light show thats going on while they're driving, you can't use it for anything else.

Lmao couldn't of said it any better!

 

[MotoEclipse]

..well i got the narrow band for free so its not like i wasted any money on it. but it does look cool ...

 

[jed344]

the only time i would be scared of what a narrowband says is if i was in WOT and it pegged lean. otherwise it will just flash back and forth and peg rich when you get into it

 

[gofer]

Rich to a narrowband is anything above .7v but my WB is showing 12.5:1 and my front o2 sensor is reading .9v and at WOT on pump gas 12.5:1 is LEAN but your narrowband will still show rich.