More tuning questions for the Gods

[Rusty McNeil]

OK, so heres the run down.
I got my swing arm and pumpkin back yesterday, put the bike back together and took it for a spin; minus my body work I'm still waiting on.
I have a data logging Wideband Commander a/f setup and took it out on some straight back roads and ran it through it's paces while logging.
Ran it from 2000rpm to redline in 1st thru 4th gears, one gear at a time, of course it was boggy in 3rd and 4th starting at 2000, ....doesn't concern me.
It feels just fine to me, and data logging shows it staying between 12:1-14:1 all the way from 2000rpm to redline so I'm Ok with that, may try and fine tune that some later to get a steadier a/f of around 13:1 , the higher the rpms and the slower the revs climb it gradually rises to 14:1
Steady cruise shows no signs of the dreaded surging I've heard about, and it will accept throttle input under just about any concievable conditions.

Here's my concern..

When just "cruising" at steady part throttle at about any speed it's showing around 18:1 or so.
I don't mind lean when I'm not asking for power, but 18:1 when running a STEADY 80-90 miles per hour seems lean?
As long as I'm ACCELERATING it's good, but as soon as it steadys off at a fixed speed/RPM then it goes back up to 18:1
My other big concern is that 18:1 is the limit of the a/f sensor, the needles is pegged, so for all I know it could be much leaner than that. I'd like to fatten it up some just so I KNOW where it's at.

What part of the carb do I need to play with to fatten up the cruise a/f without screwing up the rest of it. Is this a PAJ 1 or 2 adjustment, a needle adjustment, or both???

Running
Stage 7 with K&N filters
Stage 7 springs and needles with clip on 3rd groove from blunt end
165 DJ mains
PAJ 1 and 2 are stock jets
Full Exhaust
Fuel bowl vents in place and up near the air filters
Idle screws at about 3.5 turns out.
Float levels set per Marks sticky, can't remember the number; 16-17mm maybe??

 

[maleko89]

Rusty, think it's pretty normal at least at lower rpms. Easiest thing
To play with is PAJ2's. Try going lower..maybe start with Mikuni 165
Or 160's. You can try turning mixture screws out too.

 

[one2dmax]

Lean at part throttle positions is fine and won't hurt anything. That's what helps get your fuel economy. 13:1 is your target a/f when under load (and your faux tank cover and scoops in place).

Sean

 

[gamorg02]

as long as its not studdering either

 

[Rusty McNeil]

Lean at part throttle positions is fine and won't hurt anything. That's what helps get your fuel economy. 13:1 is your target a/f when under load (and your faux tank cover and scoops in place).

Sean

Thanks for pointing that out, I did consider that without the cover in place my numbers might be off from what they are going to be later....

PAJ 2 stock is 170 Mikuni right?

I may try to go that route just enough to get it on scale so I can be sure it's not off the charts lean.

If anyone wants to see the log I can send it to you.
You need this software to view it, takes about 20 seconds to download it. Really small file.

It will only show RPM and a/f.
Adding a TPS to it would make the file much more useful, as it is you kinda have to know under what conditions you logged it. I can't seem to find a TPS sensor that doesn't cost a million dollars. Most of them need a 5 volt source...
Does the vmax Pressure sensor use 5 volt source or is a a 12 volt source?


http://www.dynojet.com/newdynojet/downloads/Default.aspx?ProdType=Widebandcommander

 

[one2dmax]

I'm pretty sure it's a reduced voltage unit. Not sure but you might be able to convert a Royal Star TPS and make the mounting adapter to fit it (since it's also setup for V4 configuration).

Sean

 

[Rusty McNeil]

I'm pretty sure it's a reduced voltage unit. Not sure but you might be able to convert a Royal Star TPS and make the mounting adapter to fit it (since it's also setup for V4 configuration).

Sean

I'm going to check in to that, if the pressure sensor already has a 5 reference volt supply to it I could use that to power/reference a TPS. I did find a universal TPS from edlebrock yestedray, it's a 5 volt unit as well.

I really would like to have the TPS input to the WBC, the graphs would be much more meaningful that way.....

 

[Antwerks]

rusty the easiest is to change clip positions - it sounds like you are running lean inbetween 1/4 to 3/4 throttle and the only thing that will give you lean is less than adequate fuel and in this range the simple fix would be go down to 4 clip position, you will be fat at the front but on target where you usually ride - FAST! not sure where i was on my stage 7 when i had it... when i had my bike dyno'd with the stage 7 in it i was running 14.7:1 A/f, the guy in humble said it was on the money? go figure.... you can change the clip position in a minute it would tell you something quickly... but hey...i could be wrong...lol