Nobrakes, Do you any schematics for your setup? Do you just filter the sensor output? Do you get steady results?

 

That's all I'm doing - reading the sensor with the A/D converter and averaging the results, updating about 10 times per second so it gives a nice smooth reading. My plan was to also sense RPM and build a profile of a/f mixture vs RPM like that Innovate unit, that I would then download to the PC and make purdy graphs. Hence the big box and not just a voltmeter. But I never got around to the RPM part of it, and now my bike is dialed in good, so that project got back-burnered a little bit, maybe forever.

 

I decided to go with the K&N kit that I referenced above. Finally got my Muzzy and drilled the hole. I'm having the fitting welded on tomorrow.

I'm going to try and dial in the stock carb while I'm waiting on the Mikuni TM33(34) from Bill Blue.

 

Dan,your info on the stock carb will be very helpful for those of us that are currently stuck with the stock carb. [:@] Unless I am forgetting something, I don'tthink anyonehas used an O2 sensor with the stock carb yet. What elevation are you at? I see you are in Colorado, so I am figuring you are quite a bit higher than many of us. Either way, it will be good to have some real data as a line in the sand from which to extrapolate for our own elevations.

Thanks for taking the time to do this on your stocker.

 

You need to remove or clamp off the air injection system to the header as it will skew results if you dont.

 

Northern Tool Company has the perfect tool for fuel/air mixture specially on these 1 cylinder bikes. It's called a color tune combustion tester. It is a spark plug with a window in the top to see the color of combustion . Different combustion temperatures are different colors so a chart that tells you what color means rich, lean, right on etc... The tool runs 60 bucks and works very well. Hope this helps ya

 

Installed the K&N Air Fuel Ratio Monitor kit and spent the past few days playing with the carb settings. I've become pretty fast at getting the carb on and off (even faster than the carb rack on the ZL900 eliminator that I had for 18 years). I believe that Ihave my bike's carb tuned pretty well now.

Here's my setup/environment:

Modded stock carb CVK34
- 7/64" slide drill
- N1TC jet needle - 1st clip
- Kouba fuel mixture screw - 1 - 1/2 turns out
- Keihin 128 main jet
- (replaced float bowl and vacuum valve cap screws with socket head cap screws)

Smog stuff removed and capped

Crankcase breather mod - capped airbox hole and ran a 19/32" PCV hose up to the top of the airbox with a K&N crankcase breather filter

Backfire screen removed

Airbox lid off

K&N Air filter

Muzzy full exhaust system with quiet core and spark arrestor screen installed

Altitude: 5000'

According to the monitor (tests done under load):
- idle set to ~1350 RPM and the mixture is spot on
- up to 1/4 throttle good but goes a little rich
- 1/4->1/2 rich
- 1/2 -> 3/4 rich to good
- 3/4 -> WOT - good

I'm a bit rich in the low midrange. I started out with the clip on the 2nd notch and I was really rich with a lot of popping on deacceleration.
Moved it to the 1st notch and things got better with only some occasional popping. I'm considering putting the stock needle back in and
adjusting it with some washers.

As for the feel of things, pulls real good up to about 8000RPM, a little stutter there but I usually shift before then anyway. Under load and WOT, pulls hards all the way.

The O2 sensor and monitor is a temporary install for tuning. I'll use it a couple more times for tuning the TM33/4 and 330cc kit.
I traded off "destroying" the headpipe against taking a scientific approach to tuning. If the appearance of the fitting and cap gets to me,
I may get another headpipe (but I doubt it).

 

Nice job!