I had a 99 CBR600 with the same engine but carburated. As far as I know the Hornet is fuel injected just as the later CBRs.
You need fuel, spark and air.
I doubt it's the fuel, because it would then run rough over the entire rpm-band. Nevertheless it wouldn't hurt to check the the fuel-filter, because if it's clogged up - it's worth changing anyways and doesn't cost much.
Spark - check the spark-plugs. (drive around for ten minutes to have the engine warm up. When you get back, switch it off right away. If you let it idle for a few minutes, the spark plugs will be black) They should be brown or a bit grey. If they are black-you have too much fuel - probably the air filter is clogged up or the distance of the electrodes is too big. If they are white, your engine runs too hot and lean. maybe the fuel filter is clogged up or you have a problem with your injection system. Of course make sure you have the right spark plugs, but I suppose they are still the original ones.
Air. Airfilter is obvious, but as far as I can remember my bike had a switching air intake for low and high revs. It could be that the intake pipe for the low-rev range (those are the longer pipes) are clogged up. Could be insects for example. - You could check with an endoscope. I bought one for 60 Euros or so and it works fine. Not great, but good enough. Otherwise I'd remove the assembly and try to clean it with some compressed air and a can of Carburetor and intake cleaner.
I had a 99 CBR600 with the same engine but carburated. As far as I know the Hornet is fuel injected just as the later CBRs.
You need fuel, spark and air.
I doubt it's the fuel, because it would then run rough over the entire rpm-band. Nevertheless it wouldn't hurt to check the the fuel-filter, because if it's clogged up - it's worth changing anyways and doesn't cost much.
Spark - check the spark-plugs. (drive around for ten minutes to have the engine warm up. When you get back, switch it off right away. If you let it idle for a few minutes, the spark plugs will be black) They should be brown or a bit grey. If they are black-you have too much fuel - probably the air filter is clogged up or the distance of the electrodes is too big. If they are white, your engine runs too hot and lean. maybe the fuel filter is clogged up or you have a problem with your injection system. Of course make sure you have the right spark plugs, but I suppose they are still the original ones.
Air. Airfilter is obvious, but as far as I can remember my bike had a switching air intake for low and high revs. It could be that the intake pipe for the low-rev range (those are the longer pipes) are clogged up. Could be insects for example. - You could check with an endoscope. I bought one for 60 Euros or so and it works fine. Not great, but good enough. Otherwise I'd remove the assembly and try to clean it with some compressed air and a can of Carburetor and intake cleaner.
Your comment states that you doubt if it's fuel related? Yet reading your statement you advise the Op to check all fuel related issues?.
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