Is anybody using a hand held A/F meter that they would recommend?
I'm looking for something with a probe to stick in or near the exhaust, not something that has to have a sensor on the headers or mounted anywhere on the bike. Just seems like knowing where you're at and knowing where to adjust would justify the cost over having to tinker with jets, and A/F screws, as a hit and miss science and wasting valuable duning time.
I love my TM45, but from Saturday afternoon at Dumont to Sunday morning, and a 35 degree temperature swing, I went from azz haulin to stuttering and stumbling. Yes, even after the engine warmed up... If I could have just turned the screw and dialed it in real fast it would have made the sunrise trip to the North Pole much more enjoyable.

 

Single cylinder motors will give you a leaner than actual reading by putting a sensor in the tip of the pipe due to the oscillations of the air around the tip of the pipe. It is best to use an O2 sensor bung welded on the pipe further down closer to the motor. I have confirmed this by testing my motor with the sensor at the tip and in the bung and the readings were greatly different. I have used the same sensor on my street rod at the exhaust tip and was able to get accurate readings as it has more than one cylinder and doesn't suffer from the same exaggerated oscillations. There are several out there to choose from, go with a wideband. I use the LM-1.

 

This is just me talking but for over 20 years when I used mikuni carb they seem to be very temperamental on air temp and elevation, again my personal use with 2 strokes and soem 4 strokes.
29 palms is 2000 to 2500ft ele
Dumont is 700 to 1200ft ele
if the DS was tuned for 29 palms it would run leaner in Dumont.

 

The only ones I have seen with a probe that slides into the exhaust, are the ones that work with dynos, and cost in the thousands. I had a Autometer narrowband A/F with the welded in bung in the exhaust on my Predator, works ok (basically just tells you if your lean or rich), but not great at all for tuning as it is narrowband. I just ordered a PLX wideband tuner that I am gonna use on the DS when the 46HV gets here. I thought I ordered the data logger one, but found out I didnt, o'well to late. Innovate also has some nice wideband tuners. All of these you have to weld a bung, but when I was done with it I just pulled the O2 sensor and put the plug in the bung and done. If you run leaded race fuel I wouldnt bother with it. I burnt out my O2 in about 2 hours of playing with it running leaded fuel. I knew it would burn out, just wanted to check it out.

Chris

 

Narrowband meters are made for cars usually. Cars run lean compared to bikes. Narrowband meters read + or - 14 to 1 A/F. That's way lean. Bikes run closer to the 12 to 13 range.

Wideband like the LM-1 will give you a true reading if you get the bung placed right. I put one on my KFX730 on the rear pipe about 18inches from the exhuast port and halfway from the end of the pipe. It's very important to check for exahaust leaks as the LM-1 will give a false lean if there is any leaks.

LM-1 is really the only way to go if you want this done right. They are around 350$ with one O2 sensor and one bung.