Cooling system anomoly

[AGENT 37]

1999 Yamaha F80

When the motor is running in the water or on a flushing adapter I get a good tell-tale stream.

When I hook up the yamaha hose adapter on the topside and flush with good water pressure I don't get the good tell-tale stream but I get plenty of water coming out of the exhaust.

What might this be an indication of?

 

[capt sam]

Re: Cooling system anomoly

my stream is weaker off the hose adapter because there's no impeller pushing the water thru the head.