Tuning with A/F Lambda meter
 

So I ordered one of these guys and it'll be here tomorrow. I also got a used factory header from the last part out on here and I plan on modifying that with the o2 sensor bung. My plan is to get the best all around tuning for dual sport riding. I'm at sea level and I ride up to about 7-8k feet, I've seen 10k but thats far and few between. Like any testing and tuning this will be a long process but I'm excited to get a baseline. The way my bike is now, per my signature, runs pretty darn good. I'm looking to optimize the compromise between the SF Bay Area and the Sierra Nevadas. I'll error on the side of running better down here of course but if I can improve what little power is left at 8k feet that would be sweet. Also, my bike gets a pretty solid 50 mpg....maybe less...not complaining but its pretty decent drop from stock. I have a SpeedoDRD and my MPH is dead on (I know, now my odometer is off). Tracking MPG is tricky and very subjective so that will mainly be for my own interest I suppose but I'll definitely share any useful findings or improvements. Non the less if I can get back to 55-60 mpg that would improve my range nicely.

If anyone has some suggestions or tips I'm all ears! Hopefully we can get some better tuning data??? Who knows, the mod spread sheet is pretty good and worked well for me but what the hell, I've always wanted to try this!

Digital Wideband UEGO AFR Gauge | AEM

What was the cost of the gauge/sensor/etc?

Looking forward to seeing your results as I am at 5k and go up to 7k occasionally. I've ran your current jetting with no lid up to 7k with no noticeable problems on the buttdyno so it will be interesting to see what an actual A/F meter reads.

thanks for sharing. cheers

It was 165 on Amazon prime, I ended getting an extra bung for another vehicle I want to check out and I got a gauge pod. My plan isn't to permanently mount it but use it to tune and call it good.

So far I haven't had any real complaints about my current set up except on gnarly steep hill climbs my bike bogs. I'll use first or second, slip the clutch, keep the revs up and it still bogs. I've checked the float bowl level but I might need to take a second look at that. As far as jetting goes I guess we'll find out how close I am. I think there is more to be had as far as mpg and crispness on throttle control.

I had the same issue when I was running a DJ124 @4N with my lid off and my stock exhaust.

I strongly suspect you're running quite lean with a 128 at sea level, but we'll see once you get that gauge hooked up.

I'm pretty sure I've tried the 132 and had mixed results as far as introducing other little hiccups. I remember after I did the current jetting and mods my bike seemed to run cooler than stock, at least as far as the header heat on my leg goes. I know thats totally subjective but I'm sure its less lean than stock which is a step in the right direction. Honestly I wouldn't be surprised one bit if its still lean, I'm thinking if I get it pretty close to stoich I'll have good power and good fuel economy. I'm curious to see how much lid vs no lid effects it. Ideally if I got the carburetion pretty good across the rev range down here then went lidless at high elevation that to correct for the richness that would be sweet!

Oh, I also run a filter sock on my Twin Air...not sure how much that matters either. I usually pull that off and just run the filter on my second or third day of dirt riding.

You best power isn't actually near stoich. It's about 12.6 - 12.8:1 under WOT. Stoich is a good spot to aim for under light throttle cruising though.

Norcalklx, where are you in the bay area? I live in Concord, work in Berkeley. It would be awesome to be able to rent your set up, once your done tuning, to tune my 2007. I have the same slip on, but currently have a BB mikuni pumper carb on it.

If you're using 10% ethanol, max power is at around 12.2:1 btw

The magic box takes all the work out of tuning! It's over quick and there's nothing left to do when you get it zero'd in.