Jump to content
Sign in to follow this  

LM1 fuel/air meter?

Recommended Posts

anyone use one on your bike?

where did you mount the sensor if so?

Would they work for a 2-stroke as well?

I'm very interested in these, they seem to the the perfect way to tune for new parts, or locations. They even let you record 44min of riding, then you can plug it into your computer and see how your jetting was on a graph.

Does anyone have pictures of them on your bike?

Share this post


Link to post
Share on other sites

The oxygen sensor gets mounted in the exhaust header fairly close (8") to the engine as the sensor must be HOT to operate. Two strokes will contaminate the sensor with the premixed oil.

Having 44 minutes of recorded information would be good under a controlled set up, like on a dyno. If you went out and rode a couple of laps on a mx course and then examined the data, you wouldn't know what riding conditions produced the results, like engine load vs. throttle setting.

If my memory is corrrect, the LM1 uses a wide band sensor. THAT'S GOOD!! And more expensive. The circuitry to drive and monitor the sensor is much more complex than for a narrow band sensor.

The lower priced air/fuel meters use a narrow band sensor.....not good.

The ideal setup for the bikes would be a wide band sensor and LED read out.

Ride on

Brewster

Share this post


Link to post
Share on other sites

Ok so they will not work with a 2-stroke. darn

I guess I'll need to buy a 4-stroke soon! ha maybe one of those new KTM sx250f...or that new CRF250r. I have the perfect 250 class ride already. I guess a 125 class bike would be nice. Get to do more riding, maybe even a little 125 class AX racing.

they have an LED add on for the LM1 meter...nice

Share this post


Link to post
Share on other sites

Okay I remember seeing that in the past. Looks pretty awesome, but a little pricey still.

Share this post


Link to post
Share on other sites

Ok, so is there a way to go to the auto parts store and pick up a car oxygen sensor for less than 40 bucks and test a cheaper way? I will look into this some more to see if I can find out exactly what kind of measurements would need to be taken and how to record them. But does anyone else have any input?

Share this post


Link to post
Share on other sites
Ok, so is there a way to go to the auto parts store and pick up a car oxygen sensor for less than 40 bucks and test a cheaper way? I will look into this some more to see if I can find out exactly what kind of measurements would need to be taken and how to record them. But does anyone else have any input?

Like I said in my previous response, the narrow band sensor is NOT designed to operate over a wide air/fuel ratio change. It is designed to basically switch at 14.7:1 ratio. For max power, you're looking for a 12.5 to 13.5 ratio. A wide band senor will do that but, the wide band sensor needs much more complicated circuitry to operate and read out the air/fuel ratio.

Ride on

Brewster

Share this post


Link to post
Share on other sites

OK, I have looked into it some more and it seems the oxygen sensor from a 92-95 Honda Civic VX would be a readily available wideband sensor. I have seen prices from as low as $65 (Arizona Autohaus) to as high as $450 (Napa or something). In order to use that sensor you have to make a $250 wideband controller, so it saves you no money and gives you a bunch of work. I'm a jetting newb and was looking for a cheap and easy way to HELP with the tuning, this is not cheap but definately useful. Time to kick around some more ideas.

Share this post


Link to post
Share on other sites
Go over to KTM talk and look in the "product review"section or go to www.bluetraxx.com and read about the jet*4*power meter on the home page.

The jet*4*power uses a narrow band oxygen sensor. The response of these sensors is NOT specified by the sensor manufacturer in the range that the jet*4*power is being operated.

Ride on

Brewster

Share this post


Link to post
Share on other sites
They must have a trick to it that you don't know about. I just picked up the Sept. ATV Sport magazine and the featured quad has the jet*4*power meter installed. They say it works great! No offense Brewster, but a magazine would not endorse a product if it didn't work. I'm buying one today! I also did a search on bluetraxx and read the review . All of these people can't be wrong either. :D

Hey, it's your money. Go for it.

But, before you do, contact j4P and ask how they calibrate their units and what air/fuel ratios the leds represent.

I had some dialog with j4p about a year and a half ago and wasn't impressed with their answeres. BTW, I've got over 20 years of electronic instrumentation calibration and repair. Also got a Cal. smog license back in the 80's.

I also designed and put together a similar devise just to see if the idea would work. Total cost for parts was $10, plus another $25. for the narrow band sensor. My conclusion is that the electronics can be made to work very well but the sensor is still the wild card. For accurate readings, each sensor should be matched up with the electronics and calibrated with a CALIBRATED wide band sensor type meter or an exhaust pipe sniffer, like they use to do the smog checks here in California.

Ride on

Brewster

Share this post


Link to post
Share on other sites

Hey guys, here's a link to DIY kit. http://www.techedge.com.au/vehicle/wbo2/default.htm

The Jet 4 Power meter looks to me like a few other A/F ratio meters that have been available for some time, they are basically useless for any real tuning. They make for a nice light show.

Do a google search, there are a few nice wideband kits on the market now.

I'm with brewster, save your money.

Share this post


Link to post
Share on other sites

your sounding dangerously close to a person that is involved with j4p.

there is a reason that they were refunded the paid advertising money by TT.

Share this post


Link to post
Share on other sites
If they are so useless, then why does the JD jetting website show them on his bikes for tuning? Didn't he also state a long time ago that the j4p unit was used to get the parameters for his jet kit on the CRF250? Didn't JD also have the j4p on his bike and talk about how well it worked?

:D:D:D !! Busted !! :eek::eek::eek: It's Mr. 911 returned under a different name. You can disguise your name, but not your histrionics dude. We know it's you. Be gone, wacko, be gone!

Share this post


Link to post
Share on other sites

When I said "basically useless" , I was referring to A/F meters using narrow band sensors. No respectable tuner is going to rely on a meter with a narrow band sensor.

I'll say it again, save your money.

Doesn't anyone read spark plugs anymore ?

Share this post


Link to post
Share on other sites
I was referring to A/F meters using narrow band sensors. No respectable tuner is going to rely on a meter with a narrow band sensor.

AMEN to that. :D

The only time a narrow band sensor is useful is when it's tied on the end of a plumbline while hanging sheet rock. :D

Share this post


Link to post
Share on other sites

the lm1 unit works nicely as does the dynojet wideband commander.

the wideband commander is the stand alone version of the a/f meter used on the dj dyno itself.

http://www.widebandcommander.com/

neither is cheap.

narrow band sensors only know when the a/f ratio is 14.7 to 1.

on motorcycles,the optimum ratio for power is 12.8-13.2 or so at wide open throttle.basically,as said by others the narrow band unit is useless.

Share this post


Link to post
Share on other sites

so is it a good idea to use an A/F to tune bike engine?

If you search on net you can find how to build an A/F meter yourself.

Share this post


Link to post
Share on other sites

How do we understand if the the engine is running reach or lean? maybe it is OK to use a setup that someone has tested it on a dyno but what if you have different parameters (different tuning)? how can you get a good setup if you cant have dyno access? I really wonder how do we know if our carb has a correct setup only by making some clicks as someone else did on his bike? Even the air has different density from town to town or even in city center related to suburb. If you cant measure with some kind some parameters, then how can you be sure that what you have done is correct? so isnt a good idea to use an fuel to air meter? I hope my question make sense.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...