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Finally an affordable AFR meter brought to you by KOSO !!
This instrument shows you the air/fuel ratio in the exhaust gas.
This is the ONLY way to accurately jet or tune your moped or scooter!
The display shows the AFR ratio on the easy-to-read LCD. The higher this value, the higher the remaining proportion of oxygen.
The ideal value is 14.7 (this means 14.7 : 1) when tuning for economy, on a 2-stroke for ultimate performance and engine safety you should be aiming at 12.5 to 12.8.
Anything much above 14:1 on a 2-stroke is too lean and you start to risk seizures through piston overheating. Anything less than 12.5 is safe, but you start to lose performance and smooth running much below 12:1.
To fit you need to drill a hole in your exhaust and weld in the threaded boss into which the lambda sensor screws (supplied). On a 4-stroke the lambda can be left attached permanently, but on a 2-stroke the oil in the exhaust gases will damage the lambda over time and it should be removed and replaced with a plug when not being used to setup the bike.
Additional bosses can be purchased cheaply which means several people could fit bosses to their bikes and share the AFR gauge whenever setting up making it very cost effective!
To test, the reading should be taken only when the scooter is under full load and at full throttle and the main jet adjusted accordingly until you are within the 12.5 to 12.8 range.
KOSO KO-BA005000
Hi, it depends a little on whether you're tuning for economy/ max power etc.
13.0-13.3 is a good safe reading, it would be fine to run it a little leaner on a 4-stroke (say 14-14.2). You would aim closer to 12.5-12.8 on a 2-stroke (higher risk of seizure if it gets lean)
Yes, the oxygen sensor is included with the kit. This would work fine with a car and could be left permanently installed, but keep in mind this is a narrow band oxygen (Lambda) sensor.
A narrow band Lambda will basically tell you whether the mixture is stoic (correct) too rich or too lean at any given moment. A wide band sensor does the same but it will tell you exactly by how much the mixture is too lean or too rich with an exact reading. A wide band AFR kit is much more expensive though.
As soon as we get new stock for Koso Mini LCD Air/ Fuel AFR Meter, we'll send you an email.
