CBR F3 running rich, dyno pic inside!

[alan0259]

I had my 1998 F3 on the dyno the other day, the bike is standard engine wise (to my knowledge) apart from a stubby can (which I put on).

I've been told that the air/fuel ratio is running very rich, its down to 10:1 in places when it needs to closer to 13:1 and that it's wasting fuel and power!

I've just been offered a K&N for this model fairly cheap, do you think this would improve it at all until I get it to the garage? My exisiting air filter is a few years old according to my knowledge...

Local mechanic said I would probably get away with going down a few sizes on the main jet. Can I just buy a different size main jet and replace it myself? Or would it need to go on the dyno to know exactly what size to buy?


Thanks



https://i890.photobucket.com/albums/ac107/alan0259/Dyno.jpg

[robocog]

No tourque curve?

Important bit is its not piston meltingly lean (esp at the higher RPM) so at least its "safe"

Better to be running rich than rebuilding
If its not bore washing or eating plugs its a good result

Sticking a K&N on or a fresh new one I would have thought will lean it out (if its running carbs and your old filter is not in good order)...but by how much? going to have to chuck it back on the rollers on a cold day and then see

Regards
Rob
____________________
Needs a bigger garage...