Overheating

I need help!!! My boat is overheating!!! Here is what I have done so far. Replaced impellar, thermostat. The boat will run fine on the hose when I hook it up at the strainer cup. Then I went and put it in the lake again and noticed that it is not drawing water from the lake into the strainer cup. I then ran a hose down that hose to the intake under the boat and it was not clogged either. I even switched strainer cups and rubber washer with a friends and it did not work... however...if I bang on the strainer cup... It will eventually pull up water and then once it is full, it stops pulling from the lake.. does anyone think that ir could be the entire strainer assembly? I have checked every hose and clamp to make sure I am not drawing air anywhere. The water circulation pump would be my next step, but I have never heard of them going bad without leaking??? Any help would be great... I may try bypassing the strainer all together to see if it is that...   Thanks!!!

I did, I even turned the pump over and tried it.... It was overheating before I changed the impeller and the impeller did not look bad when I changed it.... Ran great last year and I have been winterizing my nautiques for 20 years and never had any problems like this...except one and it was a cracked strainer that was letting air in..

Thanks and I will get some pics on here soon!

well I would disconnect the hose at the strainer and then the hose coming out of the RWP, stick the hose from the pick-up side into a bucket of water, start the motor and verify you have the impellar installed correctly and that it is actually drawing water through the RWP, no need to jack with the circulation pump as that is further down stream and will not effect the flow to the RWP (Raw Water Pump).

now if this verifies you have water flow then something is wrong between the strainer and hull pick-up. Might have a hairline crack in the strainer somewhere causing the issue. Might have left a small amount of water in the strainer over winter and cracked it.

But it seems like you know about the impellar in the RWP and with the pressurized water working fine, it seems like the strainer is the cause and there has to be a crack or leak somehwere in that genral area.