03 600 Hornet problems

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#1
Hi,i have a 600 Hornet running bad in low revs, anything above 4000 rpm no probs, only 3750 miles on clock, has anyone come across this prob before..??:Mad2:
 
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#5
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.
 

Rs2k_Rider

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#6
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.
Earlier ones are carb mate. Its the newer ones that are injection.
My 99 was carb.
 

miggy

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#7
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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#8
Hi Guys, My Hornets standard cards, early 2003, its not fuel inject, picing up a set tomarrow to try on it, Thanks again for the in put..
 
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#9
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?.
Well not quite. I'd start with the spark plugs. Checking them will usually point me in the right direction. Given the fact that the motorcycle in question doesn't have a lot of miles on it, I'd guess it's some form of dirt/insects and not excessive wear on some part. If I had to place a bet it would be some sort of build-up in the intake manifold on the longer pipe for the low-rev-range on one of the cylinders. That way in the low-rev range one of the cylinders will run too rich, not fire appropriately which will give a rough running engine in the low-revs and a fine running engine in the high-rev range.
But over the net this is of course all just wild a$$ guessing.

I've just read it's carbureted. Well in that case it can also be just dirt in the bypasscanal of the carb. That canal is tiiiny and if the motorcycle is not in use for a few months the petrol will evaporate and the parafins, oils, waxes in the petrol will form a guey residue that will then clog up the canal. - A can of carburetor cleaner should hopefully help, otherwise you will have to disassemble the carb to clean it properly, but I'd take it to a shop for that work - they put the carb housing in an ultrasonic bath, which is a lot more effective than manual cleaning. Plus they know how to adjust the carb properly, which is a pretty complicated task if one has never done it before.
 
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#10
Hi Guys, u,ll be glad to know l got the hornet sorted after a lot of testing , turned out it was shims at the inlet on No 4 cylinder, Changed both shims and bike running sweet,, :Cheers:
 
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#11
i have the same problem on cbr 600rr changed spark plugs but still bad.
 
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