Put wideband O2 sensor on bike tonight. Interesting..

Hooked the wideband up the the bike tonight to figure out some things with my jetting. Wide open throttle seems to be right on at 13.2:1ish with 115 main jets. Half throttle seemed spot on too. Problem is that I am very rich at light throttle when cruising.

This tells me that I need to drop my pilot jets down a size. The wierd thing is that I still have the stock 115's in there. And this is with pod filters and kz750 cams. Seems to me that I would need to go up a size on the pilots not down. Anyone know why this is?

I had to do it on my Yamaha Vision years ago when I redid the exhaust and started the jetting process. I think we even went down two sizes.

I never did really figure out the reason, but it really woke the machine up.

This is odd indeed.

Did you retain your 650 head?

My engine (700cc piston/jugs 750cams pods/4-1) was installed on a 650 head and jetted for that first,

I found that the pilot jet was 1 size too small and the needle jet needed to be opened up to the maximum richness too.

How did you install that sensor? Sounds very useful especially in critical areas in 2-stroke tuning.

If I could instantly now how lean/how rich my motors were running that would be a big deal.

Thanks!

Where are your pilot screw air jets set ?u may be able to lean it out enough buy turning them a bit,before u try replaceing the pilots.can u show me a link to your o2 sensor?i would like to read up on them.

Yea, I have my pilots out about a quarter turn to make it idle well. If I turn them in all the way it idles rough.

Wideband is a Tech Edge buget unit from, wbo2.com/ . I ended up building the DIY one to save some cash.

Post edited by: kxhonda, at: 2007/08/15 11:12

are u out a 1/4 turn from seated?if so that woud be an indication that the pilot is too small.general rule would be less than 1 turn could stand to go down a size.those 02's are $$$$.how did u make ur's?how much $$?

mark1122 wrote:

are u out a 1/4 turn from seated?if so that woud be an indication that the pilot is too small.general rule would be less than 1 turn could stand to go down a size.those 02's are $$$$.how did u make ur's?how much $$?

Less than $50 for the wideband O2 sensor from Amazon.com, and the wideband controller is $70 in kit form and $90 assembled (with display) from www.14point7.com/JAW/JAW.htm

Is that cheap enough?

Post edited by: steell, at: 2007/08/19 11:58

steell wrote:

mark1122 wrote:

are u out a 1/4 turn from seated?if so that woud be an indication that the pilot is too small.general rule would be less than 1 turn could stand to go down a size.those 02's are $$$$.how did u make ur's?how much $$?

Less than $50 for the wideband O2 sensor from Amazon.com, and the wideband controller is $70 in kit form and $90 assembled (with display) from www.14point7.com/JAW/JAW.htm

Is that cheap enough?<br><br>Post edited by: steell, at: 2007/08/19 11:58

I'm considering the kit with the display, but still have a few details to learn.

How much current does the whole thing use? I read somewhere the sensor's heater can use up to 10 amps.

Someone on the MegaSquirt board took some measurements that indicated a 3 amp draw until the exhaust heated it up enough, then the current dropped to less than one amp.

I think the controller with display uses 1 amp or less.

Here is a link to the thread on the MS board discussing it (the JAW controller).



www.msefi.com/viewtopic.php?t=26503

Post edited by: steell, at: 2007/08/20 15:00