Engine vibration increases at 5K
I thought I'd ask if anyone would have an idea what might be causing an engine vibration that comes on at 4.8K RPM. Now this is not a wheel vibration thing as I can recreate it in 1st gear.
I bought the bike with about 9K miles on it and I know has about 13.5K. The air filter is likely original, the valves haven't been adjusted yet. I do have a ruff spot at 3K when I transition through that but as far as I can tell that is normal until I put a PCIII in it.
Would a PCIII help with this 5K and up vibration?
The throttle bodies have been synchronized at the 1200 rpm range and it is much smoother at the lower rpm's. This was done six months ago so I don't remember if the high rpm vibrations where there originally or not. I remember it being a bit ruff across the entire rpm band before it was synchronized. I guess I could try to tweak it at a higher rpm if it doesn't try to suck up the fluid in the manometer.
This vibration isn't severe but it is definitely noticeable and I don't like running the engine in this range if I don't have to.
I would like to get rid of this vibration as it limits my desire to use half the RPM range. As you know this engine just starts pulling hard at 5k so it is killing some of my fun. Now my VTR1000F engine (Honda V-twin) is a smooth all over. Maybe that is due to the superior technology used, carburetors (just kidding).
Anyone ever have some similar vibration issue and have an ideas of what to try to get rid of it?
Thanks in advance.
Last edited by bdudemon; 08-09-2009 at 10:54 PM.