[FZ09inBKK]

co adjust can be done easily on mt's. on fz's, the co adjust needs to be done with the yamaha diagnostics tool which is supposed to only be available to dealers.

Has anyone running stock exhaust / ECU asked a dealer to adjust the CO settings on their FZ09? I was reading a thread on the UK forum which has a lot of comment about adjusting all three cylinders to a setting of 14, and this having a noticeable positive effect on throttle snatchiness, by it seems making richening the AFR (unless i'm reading it wrong which is quite possible). I'm tempted to try this (I'd do it myself if we could but it's one of the differences between MT and FZ) but before going to the dealer here I'd be interested to know if anyone has adjusted the settings and also feels it is worth doing.

Changing the CO settings in the DIAG menu [Archive] - Yamaha MT-09 / FZ-09 Forums - The largest Yamaha MT-09 / FZ-09 Forum on the Internet!

It's a looong thread so here are a couple of the more intriguing posts:

"I think 14 is the normal advice.
I dont think its power loss your feeling rather a smooter throttle with no jerkiness so it seems like less power. Triple Trouble you dynod it didnt you?

Yes mate we've dyno'd quite a few MT's now and they all run much smoother with no jerkiness with the CO set to 14 on all 3 cylinders."

AND

"Did you notice any difference when you rode it after you changed it ?

I did. Took from Gloucester to the Brecons for a spin, last night. Perfect evening. I stopped at various points to try different levels and I'm happiest with 14 (stock exhaust) the difference in 'B' is negligible but in 'A' it's remarkable. Throttle much less snatchy at low end and the smoothness when rolling on is significantly better. As long as the are no detrimental long-term effects (and why would Yamaha allow this kind of flexibility in the setup if there were.....) this is where my settings will stay. If it hadn't been for this thread, I'd probably never have known "

 

[FZ09inBKK]

Do you know what the stock CO setting is currently set to?

Just going by what I've read on that and similar threads seems that many bikes are set to 0-0-0. That said (and again just going by what I've read), some folk have reported other settings ie 5-2-5, possibly where the dealer has changed things pre-delivery. But apparently there is no specific Yamaha guidance for dealers as to what should be recommended 'stock' setting.

One school of thought is that setting to 0 leans things a bit and is thus more emissions-friendly and hence possibly mandated by legal requirements at delivery. My understanding is that setting each cylinder to 14 (I don't know what '14' represents, which I'd like to know) richens mixture, presumably all across the fuel maps.

 

[FZ09inBKK]

... just wish someone could give a firm answer to what it is that they are actually changing!!!!

+1 on that!

If the FZ offered the option to change the values from stock like on the MT I'd be very interested to try just to see what happens. After all, seems odd that Yamaha offer this adjustability on many of their bikes if it's pointless.

Seems to me that mixture settings are the key to so many of the surging / twitchiness etc experiences some have, but others don't. My guess is that maybe fuel injected engines are just more sensitive to different OAT, humidity and density settings, and that it's changes in these ambient factors that provoke some of these things. Guys who actually know about all this stuff feel free to correct me etc.

 

[FZ09inBKK]

Just saw this on one of the R6 threads. So does C1-C2-C3 on MT/FZ actually refer to the individual cylinders, like most people including me seem to assume, or does it refer to throttle/RPM bands? But in that case why only three bands not four?

"I found this in one of the yamaha proformance books.

A: Fuel injection Adjustment
Fuel injection amount can be adjusted in the following four ranges:
Code C1: Fuel amount injected at 25% or less of throttle opening and at 3000 rpm or less
of engine speed
Code C2: Fuel amount injected at 25% or less of throttle opening and at 3000 rpm or
more of engine speed
Code C3: Fuel amount injected at 25% to 90% of throttle opening
Code C4: Fuel amount injected at 90% or more of throttle opening

Before changing the settings, check the engine for its characteristics in normal condition.
It is recommended that the settings be checked with an A/F measuring instrument.
Guidelines for setting
• Code C1: At 25% or less of throttle opening and at 3000 rpm or less of engine speed:
This affects the idling stability and the feeling experienced during races.
Too rich an air-fuel mixture may foul the spark plugs.
• Code C2: At 25% or less of throttle opening and at 3000 rpm or more of engine
speed:
This affects the feeling experienced during engine braking and at initial
throttle opening.
Make a change of 2 to 5% at a time while checking for any resulting
changes.
• Code C3: At 25% to 90% of throttle opening:
This affects the feeling experienced at half throttle opening.
Make a change of 2 to 5% at a time and check for any resulting changes.
• Code C4: At 90% or more of throttle opening:
This affects the feeling experienced at full throttle.
Adjustment to too lean a mixture will lead to engine breakdown.
Adjustment by checking the A/F is recommended.
In particular, to adjust on the leaner side, make a change of 1 to 2% at a
time while checking for the result. 12 to 13 is a targeted A/F.
Throttle opening (%)"