Anyone here try one of the air/fuel ratio meters for jetting their carbs? The ones I've seen allow you to weld a nut onto your pipe, drill a hole and insert an O2 sensor then run your machine throughout the RPM range and determine where it's out of the ideal range. It seems like a great thing to have especially if you own several quads. Just curious, do any shops use them? They're not all that expensive. Hardly more than a K&N powerup kit.

 

Speaking for two stroke applications...you've got some issues with the exh output being a tad sooty which will likely clog up the sensor ports. Additionally they tend to be calibrated for thumpers. 2 strokes as we know arent that clean burning, so I think that the good fuel air mixture that didnt get trapped back in, and even during the scavenging phase the good mixture that gets pulled out, would likely throw the A/F meter way off...That's why predominately you see EGT's instead...

 

I'm mainly looking at 4 stroke applications anyhow. My primary quads are 4 strokes as well as most of my friends machines. Although I will throw a Banshee in there sometime soon! How would you calibrate air fuel mixture with the EGT? wouldnt you have to have a baseline temp to go with throughout the rpm range? Seems like it would be more complex. ??

 

I based on some of the equipment listed in your sig, was why the two stroke bias.

With EITHER an EGT or O2 sensor, you have to establish a bench mark to work from. Your reading may indicate good to go, but due to combustion variables(mainly ign timing) you can get a false/incorrect reading of what is really going on. That's why you still have to read plugs and piston color/wash and work from there.

EGT and O2's shouldnt be used as a short cut to solid old school tuning. Just used to verify and maintain...