Okay, so time to update this with some good results.


So, Barker Exhaust now installed (with DB killer in). Bought it through B&B. I had Bill request the O2 bung be installed (it's a '13 no EFI, but you'll see why later) and he recommended it go in the header bend.



The exhaust came well packed and arrived in perfect shape. I had two minor install issues. The flange that mounts to the cylinder head had a minor clearance issue and required a bit of grinding to avoid hitting the cylinder head at the lower left and upper right ears. Also, the standoff between the muffler and frame had to be cut down to avoid a minor vibration off the tie down loop behind the passenger peg. I also zip tied the brake line lower to keep it further from the hot pipe and sleeved the ends of the exhaust spring with some tubing to avoid a spring rattle.


I installed my 3d printed airbox cover (may do some iterations) and rejetted the carb. For now I'm running a DJ140 main. I think it can probably support the recommend DJ144, I just wanted to start a bit leaner because range is key to me too. It's using the DN0352 Needle on slot 1. I superglued the two washers together and the stuck them to the eclip with the slightest coat of grease (in case I need to adjust later). The fuel screw is at 2.5 turns. Starts great and I can go choke off after 30 seconds from cold engine in 50 degree weather.

I then built myself a $25 AFR meter (okay it's a narrow band lamda, but it's suprisingly telling as I ride around and watch it). The meter uses no power from the bike, it's a one wire Bosch sensor ($15 on Amazon), with that I got a 0 - 1V DC uxcell analog panel meter ($10 on Amazon). The sensor produces 0 to 1 V (Google "Lamda AFR chart" to see how it works). It doesn't have the scaling of a wide band meter, but as I ride I can see easily that it's not going lean except in a few cases where I'd expect that. I'm not claiming it's as accurate as a wide band afr setup and a dyno, but it tells me quite a bit and in real world riding. The wire from the sensor goes to the + on the meter and the - on the meter just needs to go to a frame ground. No connection to or drain on the bike's electrical system.




Bike definitely pulls great compared to before and while I may play around a bit more (jets or gearing) I'm happy with it as is.

Thanks for the input!

 

Apparently you don't know the posted process I used to create the DJ144 recipe..? Dyno testing main jets, starting with a DJ136, every jet was too lean @ WOT until I tested the DJ144. A DJ144 main jet is required in order for WOT AFR to stay at or just below 13:1

That DJ144 jet is the LEANEST jet that can be used with a full exhaust system and a lidless airbox (which you, in effect, have)..

So, I'm not sure what you were thinking, but your AFR in the upper 1/2 RPM range is going lean - way too lean for maximum power output. Perhaps too lean for safe extended WOT running !!!! And then there is the issue of the "DB killer"..

In effect, by putting in a DJ140 instead of the required DJ144 and a "DB" restrictor on the end of your slipon, you have defeated the ability of your mod combo to produce its' best power.

I certainly understand why peeps use "DB killers". If the Barker system is too loud for you, you should run the restrictor too, however, IMO, before doing so, you should bring your bike up to its' top possible performance.

If you yank out the restrictor, install a DJ144, you will have a good baseline for your testing. If the Barker has higher performance potential than the FMF system I tested (which is quite possible ! ) you will need LARGER jet sizes to test ( DJ146, DJ148, DJ150) NOT smaller !

Once you have determined which jet (DJ144 - DJ150) gives the best performance overall, you can reinstall the DB killer and determine its' effects on your (prior-existing) performance ....

Once fueled correctly, you should have 1st gear power-only wheelies (Only if starting from the correct RPM - which you will have to determine), and 1st-2nd power shift wheelies when at redline (10,000 - 10,500 rpm)..

I do not know how accurate your meter/lambda sensor apparatus is,( you ARE using a wide band sensor, right?) but you need to maintain (at WOT, 6k rpm to 10.500 rpm) a lambda of under .88 volts. Anything over .88 is too lean and must be corrected with a larger main jet size. From the looks of your meter, it would seem you do not have the granularity needed to do performance tuning as you would need to concentrate on .84 - .884 volts exclusively..

 

Re-read your post above - quote: "(okay it's a narrow band lamda, but it's suprisingly telling as I ride around and watch it)"...

You must know that such an apparatus will not produce any useful information. Narrow band Lambdas can only sense 14.7:1(Stoich) accurately, with inaccurate/useless sensing above and below 14.7 Note that stoich values for %100 gasoline and ethonol'd gasoline are different !

But, you are ready for a Wide Band kit - Meter,lambda,circuitry for controlling the heating of the element, etc etc..

Placement of the bung is very important for lambda longevity. Yours is at the opposite end of the exhaust system from where Kawasaki bungs are located - you might should research the ramifications of where yours is located..

 

I have been wondering about the stock lambda bung and what the efi does it, especially in conjunction with the smog air pump pumping air into the exhaust to burn the excess - what is the efi actually doing with the information if anything? how can it know how much the smog pump managed to pump oxygen? what will the efi do on a stock engine if you just replace it with resistors? also can you test the sensor working correctly with a multimeter?

 

So, a few comments. In my setup the location of the lamda sensor was recommended by Barker via Bill Blue and I'm not the first they've done that way. Since I wanted the option of running a single wire lamda sensor, having good heat I thought would be favorable. If it fouled it's a $15 sensor and since I only really need it for tuning I can always pull it and install the supplied plug.

The device provides useful information for my goal which is to make sure I'm not continuously running lean. It typically is running .85V. It will drop to about .60V under hard acceleration for about 0.1sec and then the cv catches up back to .85V. My goal is to be running slight rich through out the rev range not necessarily to make max power, but balance very good power (for a KLX) with range and reliability, i.e don't run lean and cook the piston or run so rich I'm fouling the plug. The analog meter is also nice because unlike digital that have a sampling interval the needle bounce gives obvious, easily visible feedback. So even if I don't know if it's bouncing between a 14.7 and 14 afr or 14.7 to 12.5, it meets the goal of showing it's not fuel starved. Narrow band are fine for that. If I'm giving up a half HP I'm okay with that. Everywhere I ride requires a spark arrestor and some check noise, on the barker the DB killer and spark arrestor are one unit, so that's what I'm tuning to unless I make my own arrestor.

To answer the later question any O2 sensor, if you can get to the wires, can be tested by measuring V or mA depending on type. If the sensor is bad the bike won't run well as the ecu on an efi will constantly adjust to keep it near what the sensor thinks is the ideal afr, but if the sensor is good on a narrow band you should see the ecu constantly adjusting fueling to around 0.5V. As it goes above that, depending on the ecu mapping it will trim fuel and below it will add.

 

Well thats what I was wondering, about the ECU trying to keep the ideal afr - how can it do it when it is pumping extra air into the exhaust before the sensor when the smog air pump system is operating? does it sense through the two wires going into the smog system or something? it just doesn't make sense to me.

 

If you're talking about the secondary air system that puts makeup air into the exhaust, those typically work off of air pressure changes (reed valve) in the engine like when you close the throttle so 1 you don't need the extra air flow from the airbox then, and 2 it's not pumping air but instead giving the exhaust some flow automatically. I've only had my klx for a month or so and haven't looked at the setup yet. Some people do block them off because they are parasitic in some ways/times. The other valve it should have (EGR) is just to let fumes recirculate from the charcoal canister back to the airbox. It's low flow and comes from extra fuel tank air pressure and may also have an open vent to atmospheric.

 

It would be interesting to know how the the reed valve air injection system set up to burn unburned gasses would be parasitic. Only way I can think of is the few ounces it weighs. You may hear about hot exhaust, but that is not a negative. Higher temps lead to faster exhaust flow, evacuation of the cylinder. Racers ceramic coat or wrap exhausts to hold in heat for higher exhaust gas velocity. Anyone who removes the air injection system expecting anything more than the minimal weight savings is in for a big surprise - there is no gain.

 

No, I agree (assuming the reeds aren't torn or leaking) since it really is only open at closed and very low throttle (high vacuum) the parasitic nature is mostly just weight and maybe a tiny amount of air turbulence at very low throttle openings when it wouldn't matter in a measurable amount. Also, cooler air is a bit more dense, but as you said flow also changes with heat. It's not something that I'd personally remove so I've never really researched why people do, other than a track bike where people do whatever they can to strip weight.

 

Hey "new" EFI guys, yall are the future for all of us - pioneers of performance to build upon the relatively small base of knowledge we have from our older european EFI membership..

Some things are "old news" though - removal of the air injection system being one.... It is nice that yall understand the nuances of this system and I'm sure I don't have to explain that open and closed loop fueling does not care about, nor attempt to control, decel AFR..

You remove it for two reasons that "crop up" when increasing the performance of the KLX - extreme header temps and decel popping.
If/when you experience one or the other, remove the system, but beware, you must remove it and cap it off properly.

KLX678, please refrain from corrupting this forum with advice (especially to "new" members ) that is based on your political/philosophical outlook, and not in the interest of "best practices" . The new members will not "see through" (to your motives) as easily as the old membership does..