2005 opti 150 -weak tell tale ??

Hi! pretty new to THT forums. New to Mercury. Just got this motor, dealer says has under 100 hrs (left over put in service 2007, warr. till july 2010) had sat in their yard 1 year. New thermostats. When first started, takes a long time (seems like a least 1 minute) for tell tale to start, and it is steady but weak. It increases intensity with more throttle. It gets real weak as you tilt into the tilt range with the prop still well under water.
The first trip i got steady alarm horn with trim out but not extreme @2200 rpm to get the bow high in some swells in the inlet, noticed tell tale had quit. thought i had plastic bag obstruction. this was in deep water.
Stayed inside, moving shallow to anchor and crab, got alarm again w/motor pretty shallow tilt, did not turn mud. Thats how i got to new thermostats and concern for what is normal tell tale. I was figuring on new water pump anyway, but boat is in water and i don't have a trailer for it yet.
My 91 Johnson 150 pees pretty strong at idle and fine at shallow, pretty extreme tilt.
Any info is greatly appreciated!!

Re: 2005 opti 150 -weak tell tale ??

Might just be an obstructed tube but a new impeller is cheap insurance in my opinion.

When in doubt, change it out