Wideband o2 sensor to tune scooter

[LMH]

That tool is perfect for that, Ive seen people using gemstones magnifying glass thing for it at the Off road park St Joseph state park. It would be nice to have if you had to do it that way.

[abreen89]

he is talking about cutting off the threads im guessing. Like bear said there are ways to look down there and see what your jetting is doing..
people are looking at the wrong place when checking a plug.

even if you had to cut them which YOU DONT it would still be cheaper to do the plug chop method over purchasing a 02 sensor unless you plan on doing more then 50 plug chops.

[LMH]

A K type EGT probe is only 20 bucks, the cheapest digital gauge is 6.99, weld in bung 25 total cost 52 bucks and usable on any engine. I spent more on mine because I use data logging for my international turbo diesel ford. Problem with digital gauges are you have to actually look at the numbers to know the temp, and with analog you can glance and know its within spec.

[kingkamehameha]

Very cool way to tune i cant wait to see the datalog results

[steffen707]

Very cool way to tune i cant wait to see the datalog results

We're you talking about the datalogs for the egt or for the wideband?

[kingkamehameha]

Wideband

[kingkamehameha]

Post up your crx specs and pics. I held the state record in highschool for fastest all motor b16a in the state. 12.9 1/4 mile on slicks! Drag radials would put me in the mid 13 secods

[maddog]

Other than running a circut pipe in which the carb + trans must be tuned to it= it will not work for street use and some carbs have 3 jets, idle/pilot/main, throttle valve has 5 settings, you can't run a bore kit on efi 2 strokes, and people think 2 stroke engines are simple, did you know that a spark plug cap has 3 pieces

[steffen707]

My buddy is going to weld the o2 bung onto my exhaust today. I've been super busy with my fiance's "honey do list". If i get around to trying out the wideband today i'll post my observations later tonight.

[LMH]

What is that guy rambling about? You can efi anything. Bore kit wont change anything on the engine but the displacement which may effect VE (volumetric efficiency) if compression is raised.
The wideband will tune just the engine and carb, not the trans. Strange guy.

[abreen89]

What is that guy rambling about? You can efi anything. Bore kit wont change anything on the engine but the displacement which may effect VE (volumetric efficiency) if compression is raised.
The wideband will tune just the engine and carb, not the trans. Strange guy.

yes he like to think he knows what he's talking about but my reading his post we can tell he doesnt.

[steffen707]

Okay first impressions with the wideband is that its awesome. No idea what the sensor life will be like, but for the little tuning i'm using it for i'm hoping it will hold up.

I left the jetting the way, took out the exhaust, my buddy welded on the o2 bung, and i put it back on. I warmed it up with just the o2 plug in, then put the wideband in.

Idle was at 13.5AFR, I took it out for a spin at about 1/2 throttle it was around 12.9-13.2, I did go WOT for a little bit and it held at 13.2 then slowly dropped down as the speed went up, it got all the way down to 11.9AFR, so I might need a 118 main jet instead of the 120. I'm leaving that alone now until I ride it more before I do more WOT driving.

What's concerning is that as 1/8-1/3 throttle the AFR goes up to 15-17:1AFR. Also if i'm going around 65% throttle and get it up to say 35mph and then back off the throttle to maintain 35 (and stop accelerating) the AFR will start to climb from 13.2AFR to 15-17:1 AFR, again at 1/8-1/3 throttle.

I know in my other thread somebody suggested I have an intake leak and I cranked down the 2 clamps on the intake/carb rubber piece. Should those clamps be on the inside or the outside of the rubber coupler? Also, i'm at 1.5 turns out on the air screw and am at a 55slow jet. It idles great, but that pesky 1/8-1/3 has me thinking something is wrong, and I don't think going up higher on the pilot is the right thing. I'll post some pics in a bit.

[steffen707]

I'm going to try and put a richer diameter needle in because that's more towards 1/4 throttle, where as the needle height is 1/4-1/2 and my 1/2 seems to be good.

[steffen707]

with a 55pilot and 120 main, with the 6kb needle that came with the carb, if i'm on the highest needle clip (leaner), i'm getting lean condition around 1/8-1/4 throttle, but idle is good, and everything above 1/4 is pretty good, right around 12.5-13.5AFR

If I lower the needle clip one spot, to the 2nd from the top of the needle, it cleans up the AFR around 1/8-1/4 throttle and its down to around 13-14AFR; however, everything from 1/4 to just under WOT is super rich, around 11.5AFR and the scooter is a total dog.

In the first scenario it appears that the needle is too far down by the jet (because its on the highest clip), and thus isn't getting enough fuel at low throttle conditions, but then when i raise the needle just one clip spot, everything else is getting too much fuel.

what do you guys suggest i try?

[steffen707]

I think i'm going to to go back to the 50 pilot and lower the clip back to the middle, and see where that leaves me for 0-1/2 throttle on AFRs. I'm hoping that lowering the clip will richen up the 1/8-1/4 area (which it has from top clip to 2nd down), and then going from the 55 to the 50 will lean things out. Hopefully they both work together to fix my 1/8-1/4 problem.

Then if things are still rich from 1/2-WOT I'll get a 118main and put that in.