I am also curious about this sound as I just put on a Yoshi SO on my 2000 R6 and did a Factory Jet kit about 3 weeks ago. Now I get the same type of sound and the bike rpm also surges at idle and constant throttle below 7000 RPM. I had posted about this sound before but the only replys I got were people telling me to buy a flo-commander. I would still like to know what the sound is and what is the root cause for the problem.
Yeah, well I guess if it's not normal I don't want it. I just noticed it and getting annoyed already. I may put the stock back on for now. I'm not sure what to do! Another exhaust? Damn not that decision again! :cuss
I wonder if this is something common on all exhausts??? Any chance you guys could try to reproduce this sound and let me know what happens, and what type of exhaust you have. I would appreciate it.
Ascenta, after hearing the sound clip of your Yosh....that puttering/vibrating sound does sound raelly odd. So odd that it made me check out my bike too. I have an 03 R6 with Blue Flame highmount S/O and I also have the PCIII w/ a Micron map loaded and stock filters. I reved mine for a bit and right around 4.5k I also heard similar to yours but not too much though.
I am guessing it might have something to do with the fuel mixture from adding the exhaust.
And I also remember, before I installed the PCIII, I noticed that puttering (also sounds like the engine is gasping for air really fast) alot more when I ride and cruising on 2nd around 5k. SO the PCIII helped alot cleaning it up...and maybe also having the appropriate map will contribute on improving the sound?
Well I tried all the other slipon maps for the R6, pretty much all the same as far as my problem goes. I did some custom editing with the software around the 3500-4000 range, not much luck. I guess I'll either have to deal with it or go back to stock :gay
mine does that too whenever I try and hold a steady speed in traffic with a very light load on the engine. perhaps this is an audible sign of the coils jumping to the cylinder head?
I wonder if anyone who changed out their coils had noticed this before they changed them out and if they still have the same problem now after the swap. Either way, as soon as I hammer it, there is no hesitation or stuttering and stammering. It might just be the way the exhaust sounds when under a light load within those rpm's ranges. But the sound in and of itself doesn't bother me.
Guys, you are jumping to conclusions wayyyy out of line here. That sound is just the resonant frequency of your intake and exhaust systems together. If you ever watched your slides in your carbs when you run the bike without the air filter, you will notice the slides jumping up and down. This combined with the intake and exhaust valves and the length of the exhaust pipe makes for one specific frequency that your engine will make that sound. It is 100% normal, and happens so fast at another frequency higher up that you cant hear it around 10,000 RPM. At the lower RPM, 4-4.5k RPM it just sounds funny. At 10,000 it is what makes the bike feel like it is ready to jump away from you if you touch the throttle. This sound is totally independant from your jet kit or what PC map you are running. Each person's happens at just a little different RPM due to different densities of air and how restrictive your air filter is and what length your exhaust is. Hopefully this helps you out. :cheers
Hey jar1075, that sounds right. I gave up on the PC3 mapping. I remember that from a physics class I took, probably the only thing useful I used in real life from college so far. Anyway, my professor did a ton of experiments showing this, how different things at specific frequencies would resonate and produce a consistent sound, almost a sine wave. **** it, I'll try to live with it - I DONT WANT THAT DAMN STOCK CAN BACK ON THERE! :hammer