Originally Posted by JimN
What do you mean by "I pushed the throttle down"? It was at idle, or WOT? If it's the LT-1, you don't want to idle for a long time.
Yes, look in the thermostat housings and see if you can find pieces of the impeller.
How long have you owned this boat? If it's new to you, buy two impellers WITH THE GASKETS and keep one on-board at all times, as a spare. The knock sensor is the plug for that side and the other has either a petcock, a plug or a T-fitting for a heater. Remove whatever is there and make sure the water rushes out, not at slow dribble. You also need to remove the plugs or disconnect the hoses on the rear of the exhaust manifolds, the oil cooler and at the lowest points of the pumps, then crank it over with the lanyard off.
Quite honestly i idled for about 40 minutes or so, as it was a beautiful morning, I was enjoying my coffee
and it was the last time it was going to be in the water. I just bought the boat about a month ago and put about ten hours on it. I had it checked at the Mastercraft dealer and it checked out fine, including the impeller. I do know about the impeller and asked at the time that it was cecked out if it should be replaced, however the service manager said that because it was the end of the season not to worry about it, but to just keep an eye on the temp gauge for any sudden fluctuation, but replace it when I winterized it. I did not know that the boat was not meant to idle long. What damage occurs with excessive idle time? We actually use it for more than just skiing and probably 2 of the ten hours have been at idle while driving around the lake watching the sunset. I removed everything thus far but have not cranked it over. I was going to change the oil, and tranny fluid, fog it and then crank it over as the last thing that I did. I pulled the entire drain plug out on the block, as I am aware how the passages get clogged with debris. Am I to worry about the pieces of impeller that may or may not be in the block, or are the passages large enough so that the flow will not be restricted?