I wasn't going to post here but now I feel I have to, the above was bad advice. I'm new to bikes and new to bike tuning, not new to tuning with vehicles in general.
The statement "you can change it as high as you want without blowing the engine" is completely inaccurate. Increasing the value does NOT increase fuel it DECREASES fuel, the lower the value the more rich the tune, the higher the ratio the leaner the tune. Rich = more fuel, lean = less fuel (more air) higher AFR (Air to Fuel Ratio) Hence a higher ratio of air:fuel will = more air.
Leaning out a tune is dangerous if you don't know what you're doing, 13.0 on an engine is actually quite high (not sure about motorcycles in general) - in cars 11.6 is "safe" for performance vehicles you lean out the tune to gain more power anything about 12.0 starts to become dangerous without proper knowledge. The R3 does not have a stock knock sensor, so you won't know if you're knocking/detonating due to not having enough fuel in your mixture so you likely also won't know "what's safe".
Nobody can tell you "what's safe" every motor is different, quality of gas is different, temperature/humidity, you didn't mention what octane you're using etc - all of these factors determine what make that value safe and will vary. If you're not sure what you're doing spend some time reading up about tuning and take it to a reputable tuner.
Edit: Meant to mention these are for values under wide open throttle conditions, I.E. closed loop operation -- at idle/cruise with static throttle position AFR's usually target 14.7 as that is stoich -- not sure on bikes if that still holds true.
Sorry if I wasn't clear I mean nobody online in the forums can tell him. I strictly advised he see a tuner as they will be able to safely tune the motor to the limits there - so yes I already mentioned it but that is correct.You are correct, I was wrong in my previous posts (so I deleted them). One thing I will argue against and bring up again: "Nobody can tell you "what's safe" every motor is different" A professional motorcycle tuner, using a dyno can tell you what is safe and set your bike to the correct settings. I don't know why this guy has a custom fuel tuner or is trying to change it if he doesn't know how it works.