25 hp mercury bigfoot goes to idle

[planetech]

Just bought a used 2003 bigfoot 25 hp. I took it out and ran fine for about 10 minutes and then rolled back to idle with no alarm waited a few minutes powered up and ran fine again for a while and rolled back. the water stream doesn't seem as strong as it was at first. Does the bigfoot have a fail safe to roll back when warm without an alarm? I am thinking the water pump but also wondering if it could be clogged with something. Is there anyway of blowing the line out from the engine out to the water pickup.

Thanks for the help

 

[planetech]

Re: 25 hp mercury bigfoot goes to idle

Does anyone have any suggestions?

 

[planetech]

Re: 25 hp mercury bigfoot goes to idle

I changed the impeller today and the waterstream is strong until the thermostat opens and then it gets weak. Is this normal or should it still be strong? I also flushed it with a water hose while I had the lower unit off and had a strong stream of water. Could it be the gasket corroded shut under the power head? Any ideas? hhhhhhhhhheeeeeeeeeellllllllllllpppppppppppp.