CNF 1000 A-6 noisy engine after engine is warmed up

[Bikeman9281]

Hi Guy's long-term problem does not seem to be getting worse but it's in the back of my mind when I go out for a ride. The bike starts and runs great when cold no nasty noises run smooth no cam chain rattle nothing as the Bike warms up there is a faint knocking noise which gets worse the hotter the engine gets been like that for a very long time I can feel it a little through the Bike. Once you stop the Bike and let it cool down it goes away baffling eh? Any Ideas Guys Thanks

[Art]

My 2006 SC58 has a light intermittent knocking or rumble, it can only be heard when the engine is at less than 2,000 RPM. Its been like that for 30,000 miles now and I haven't been able to diagnose it, it produces good power, the knocking doesn't get any worse under heavier loading and I'm getting 50 to 60 mpg, all of which adds up to mine being nothing that I should worry about.

[WileyCoyote]

Art  +1,  reassured by the second opinion  .
2009 ABS,  65K miles now and MPG as stated.
"If it ain't broke" etc.  don't fret,  just enjoy.

[Bikeman9281]

Thank you Guys that sounds like good advice I have been thinking exactly that If it ain't broke don't fix it my wife and I love our CBF   

[cancelled]

I'v got exactly same problem. When running hot i can hear and even feel some knocking noise coming out from engine. As soon as i apply some force to enging (i.e. turn on 1st gear and starting to release clutch lever) this knocking disappears completely. I personally think its somehow related to crankshaft bearings and trying to prepare myself to engine replacement. I wanted to ask if if possible to install sc64e engine instead of sc57e, cuz its pretty hard to find sc57e here(

[Gushmul]

Honestly I wouldn't worry about it too much, at certain points in the RPM range my CBF feels silky smooth and refined and then at other points it feels pretty rough. My bike definitely doesn't like operating under 2k rpm under load and makes some sad noises when I've not shifted down enough gears for my speed and I let the clutch out.

I think when you consider it's a Fireblade engine tuned to operate more like a Bandit 1200/1250 this makes sense, at times it can sound like both of those bikes. As a bit of a hodge podge combination of 600cc commuter chassis and litre bike engine it's definitely a vehicle with some idiosyncrasies.

[Bikeman9281]

Thank you all for your advice I agree with you I think that's just how the Bikes sound rough under 2k over 2k smooth and quiet