The issue is as follows:
With carb heat off:
With the prop governor set to high speed and during low-mid range power settings on the ground. As the throttle is increased slowly to full the manifold pressure will go up smoothly, but there will not be a corresponding increase in RPM it kind of stutters and stays the same for a while then finally starts to increase.
With carb heat on:
Doing the same thing as above, there are no issues.
I replaced the SCEET hose that attaches the cold air inlet of the airbox to the air filter with no change. I'm wondering if maybe the K&N filter is plugged and will check that next.
Any ideas what could be causing this? I can post video later when I figure out how to do that.
thanks.
John