[beatr911]

Universal 1 wire O2 sensors I think are about $35. An inexpensive gauge is about the same, maybe less if you shop around a bit. A bung on the exhaust is about $5 if you weld it on yourself and maybe $15 if you mark it, take off the pipe and take it to a muffler shop for the work. The sensor needs to be about 600*F to begin working and should have good gas flow in the pipe. Suggest not putting it in the crossover but in one of the downpipes in a convenient location. On the street, both cylinders will run very close to the same so there isn't really much need to monitor both.

Used with the on the non-feedback carburetor on motorcycles, the gauge will not oscillate between rich and lean like a car would. It will just stay at whatever the mixture is for the throttle setting and load. Some reading to understand how to tune CV carbs will give you a really good idea on what circuit you are reading on the gauge at any point in time while riding. No plug checks, no changing jets to see if "one more" will make it too rich or lean. The other benefit is you can see what effect temperature and elevation really have on your jetting. Guessing pretty much goes away. It's also removeable, you can disconnect and insert a plug into the bung with no ill effects. Consider a semi-permanent installation to dial in, then store it in the garage when complete.

Maximum power is achieved at 10-12 to 1 while maximum efficiency is just over 15 to 1 air to fuel while stochiometric is 14.7 to 1. So you can see that the tuners usually want to go rich and be accurate there. Us FE guys want to be very near stoch, but just a tad lean. Much leaner than about 15 to 1 and the burn slows to the point where it's still burning when the exhaust valve opens. All that wasted burn (potential work) goes out the pipe and not pushing down on the piston. The mildly rich 13.5:1, to stoch, to mildly lean 15:1 area is where the narrow band shines, it is designed for accuracy in these zones. The wideband setups are really good for dialing in rich maximum power mixtures and can be good at lean mixtures, but are overkill for our needs.

Right on fjasper! For a street bike the lowest friction is indeed a quality non-oring chain and a Scottoiler. Changing to this set-up when the stock chain wears out can net a reduction in operating cost as the increased chain life by the automatic oiler pays for itsself with extended chain/sprocket life. I don't know how much it will affect MPG though, no measurement by me.

Also I really like the idea of using filtered waste engine oil with the Scottoiler. I'm always looking for responsible uses for it. Heck, I even add it at about 150:1 to the fuel. Of course it's filtered to about 1 micron first with a homemade gravity feed toilet paper filter.