96' 225 Ocean Runner misfire 3900-4100rpm range.

[cobbcfi]

After my recent powerhead replacement I now have a misfire between 3900 and 4100 rpms only. All other rpm settings it runs fine, and unfortunately that RPM range is a good cruise setting for my boat. Any thoughts on how to adjust this?? The misfire is a muffled bang bang bang..

I am still inside of the 10 hour breaking window, about 4 hours on the motor right now, could this misfire work itself out?

 

[boobie]

Do a cylinder drop test on it when it's acting up.