3.0 overheating

[97tjzack]

I have a 2001 Wellcraft 175ss with a 3.0 Volvo that may be a newer year engine, can't figure out any info on it. Well took my boat out for the first time this year and it was overheating quickly (200 and rising) At first it was at idle, then I used the bleeder screw to bleed the air out of the system and it would run at 160 at idle. As soon as you throttle down it seems to suck air again and starts overheating. I've checked all the hoses and flushed everything. Only thing I've noticed was the exhaust hose that runs through my outdrive is cracked so the exhaust don't make it out the prop. That wouldn't cause this problem would it? Is the exhaust exiting too quickly and the water pump can't keep up? The impeller is new and all the veins spring back as soon as you remove it from the housing. I replaced the exhaust manifold last spring. Any help or ideas to check out would be great, thanks!