mis fire at low RPM

[robuilthd]

I have an 04 Busa 7k miles. The bike has 4 into 1 Yoshi pipe, TRE, K&N filter, and a Power Commander III with the yoshi pipe and filter map.
I've only had the bike for about a month and I'm not completely sure if it was doing this when I bought it or not. This miss is light but you can actually feel it in with you hand at the exhaust and see it on the tach. It's not really noticeable at higher RPMs but I suspect it is still there. It's very noticeable from 1500 - 3500 RPM.
I changed the plugs about 500 miles ago. I checked them today and they are white and powdery. I checked the resistance on all the coils and they were in spec. I have checked all of the vacuum lines as well.
Any ideas on where to look next? I am mechanically inclined but do not have a lot of test equipment.
Thanks.

 

[Blanca BusaLess]

Just a thought .
No matter how many tanks of gas you've been thru if there was the smallest amount of water in your tank from get go it could still be there ?
This could cause a stumble .

Not to difficult to drain and dry tank and start over just to make sure ?

 

[GixxerFixxer]

Take it to a dyno and get the power commander set up properly because those 'one-size-fits-all' maps are, in my opinion, a joke and should never be used... unless you're only using it to get you as far as a dyno.

 

[schleife]

Try to disconnect the air induction system.
When using 4 in 1 exhaust this system gives misfires while running on closed throttle...

Ciao
D1

 

[mike1180]

Sync the throttle bodies.
There is a DIY posted in maintenance.
Bet that does it - did it for me.