Monzamasher wrote:
I also own an 08 and and got a good deal on a set of 3" big straights so i put them on along with a K&N BAK.The pipes i got where they welded the bungs for the o2 sensors the wire was pinched tight against one of the mounts.So i eliminated the sensors and installed a power commander III usb.Went through and downloaded it to my bike and pipes and have not had any problems as of yet.I put about 5000 miles on it since, my plugs look normal.I have noticed better performance,but my fuel mileage is still about 30 mpg depending on how i ride.I am going to put it on a dyno this summer just so i can see what my numbers are.
You can put it on a dyno and remap and remap and remap but you'll never be able to emulate what the O2 sensors do at a steady cruise. I mean, they're returning a new voltage signal to the computer 8 times a second and the computer is adjusting the injector timing according to the signals it receives.

If there's any way you can get the O2's back, maybe relocate the bung or something, you'll notice a big difference in fuel mileage. 30 mpg during normal running on a FI bike means there's something wrong.

Gram wrote:
davej wrote:
River
The readings that you posted are exactly what my readings are with my carbed bike. The 11.5 is with the choke on. 13.5 at idle (at perating temp) and between 14-15 at cruise. The increase to a lean # is just as you said when letting off on the throttle and my carbed bike goes a little lean if I get it into a lugging situation. Without the AFR gauge it would have been difficult to tune my carbed bike like this (Perfect #'s in all ranges). On the OEM carb I did it by tuning the pilot circuit instead of the main jet (I used a larger pilot jet) and adjusting the needle.

Good stuff Dave. Keep it coming. Those are good AFR numbers all around. Its nice to be a little rich at higher RPMs. Helps to keep things cool.

Gram


I wish I could show you and some others here what the AFR on your bike is doing in real time while riding not on a dyno. You can see a difference momentarily with a big gust of wind into the BAK. I can adjust the PMS simply by watching the gauge and turning the screw. With my OEM carb, as I stated I adjusted the circuit that would be lean with a BAK & pipes by increasing the size of the pilot jet and controlling just that circuit with no loss in MPG. I used a #45 pilot and it brought my "around town AFR" right where I wanted it, in the mid 13's @35-45 mph where the TQ is. Some have said that the OEM carb is not as tunable as a HSR and that is simply not true if you tune it this way. It is m belief that with some of the jet kits that don't suggest that you change your pilot jet, You are depending on an uncontrolled spillage of fuel from the main jet past the needle to obtain close to correct AFR readings. I probably will never have a opportunity to see how that type of jetting would look on a bike mounted AFR gauge to compare the 2 types of jetting. And when you see the #'s in real time it is not the same as a dyno readout where the AFR is smoothed to an average with the computer. This pic is the AFR at idle Right at 13.5, can't ask for any better than that and when I turn the PMS I can see the change in real time.

What you've done Dave is much better than a dyno. I don't have any extra gauges on my bike but if I decide to add one the AFR gauge will be it.

Scott, I really enjoy everything you post, research, and verify concerning our FI bikes. you are becoming a very important asset to the Roadie FI community. We have not really had anybody that could really answer the questions and why with the FI roadies. So with that...Thank You!

I currently have my 08FI torn down doing the "Yamaha full Stage III Speedstar upgrade" so for the other readers. Full stage III = Pipes, BAK, 45mm Thottle Body, New Intake Manifold, HC Pistons, Speedstar Valve Springs, and Speedstar Cams... With that, it it is basically what a warrior would do to go stage III, the difference is the warrior goes to stage IV with high flow injectors and a new ECU.

Yamaha never produced a ECU to take the FI Roadies to stage IV, so my question is? Will the roadie's stock ECU handle the high flow injectors? The larger throttle body and manifold will definately provide adequate air. but the question that puzzles me... the limits of the stock ECU. As far as I know, I am probably the only FI guy taking the roadie to Stage III on this forum or RSR.

Thanks for your opinions and advice.


texasscott1 wrote:
Monzamasher wrote:
I also own an 08 and and got a good deal on a set of 3" big straights so i put them on along with a K&N BAK.The pipes i got where they welded the bungs for the o2 sensors the wire was pinched tight against one of the mounts.So i eliminated the sensors and installed a power commander III usb.Went through and downloaded it to my bike and pipes and have not had any problems as of yet.I put about 5000 miles on it since, my plugs look normal.I have noticed better performance,but my fuel mileage is still about 30 mpg depending on how i ride.I am going to put it on a dyno this summer just so i can see what my numbers are.
You can put it on a dyno and remap and remap and remap but you'll never be able to emulate what the O2 sensors do at a steady cruise. I mean, they're returning a new voltage signal to the computer 8 times a second and the computer is adjusting the injector timing according to the signals it receives.

If there's any way you can get the O2's back, maybe relocate the bung or something, you'll notice a big difference in fuel mileage. 30 mpg during normal running on a FI bike means there's something wrong.

Scott
As I said before ,you will not regret installing a AFR gauge!!! I can see you are the kind of guy that likes to experiment on things like this. You will find yourself trying different combinations of settings to achieve your goals. I wish I would have documented all the changes I have made before and after the gauge. I have some dyno doc's but I only did the dyno's after I was happy with the seat of the pant's changes made.Also once you know where your readings are you can see and detect the slightest problem. The AFR even gets erratic with a exhaust leak.

Really looking forward to it if I can ever get the money together. The only thing I wonder is where to install the O2 sensor. I'm thinking the crossover between the 2 mufflers but I don't know if the pipe is big enough. The 2nd choice would be in the rear (hotter) cylinder pipe I guess.

Then I would have to worry about keeping my eyes on the road and not looking at the thing all the time.

Scott, I was going to ask you what the expected numbers were. That really helps in determining how the fuel system should apply fuel, whether fuel injected or carbed.

pigpen, higher flow injectors will work in open loop mode as long as the engine air flow is increased enough so the extra flow at a given pulse width produces the proper mixture. The problem arises when in closed loop mode and depends on whether the computer can trim the pulse width enough to produce the proper mixture ratio.

It will probably be richer at idle though because whatever you do the air flow at idle will probably be the same or maybe not, only testing will determine that. That's where the new ECU would come into play. Remember one thing about the Warrior, it didn't use O2 sensors.

Let us know how it goes please. And thanks for the compliment.

River wrote:
Scott, I was going to ask you what the expected numbers were. That really helps in determining how the fuel system should apply fuel, whether fuel injected or carbed.
By numbers you mean AFR I assume. And they can be anywhere depending on engine temp, air temp, etc. That's the beauty of FI, it can trim the ratio for best economy if conditions permit.

That's all great info...