My Merc is a bit sick

[Noelm]

OK, here goes my last attempt at helping this guy, you still do not know for sure if it is overheating!!! OK with that? the chance of an impellor slipping will be remote at best (possible though) so find out what the problem is before you look for a cure by throwing parts at it, that's it for me on this one.

[SeaHunt]

no offense intended, I was reading it as being oldish and did not see that it had been replaced ,the Motor is 5 years old, and no mention of replacement, only trying to help here, if you don't like any questioning, then so be it, get someone else to help out for free, no skin off my nose.

I know, I was just having a bit of a dig at you..
And I got a bite too. if only the fish would bite like that.

The "probably long over due" bit could be taken as an inferance that I was a slacker when it came to regular maintenace, and on some things that is probably true , but not the boat, too scarey being out in the middle of nowhere and it wont go.

And your right, I don't know if it is overheating for sure, but the inpeller is due anyway so I am going to replace it and check it and also for blockages etc..
I can do it just as cheaply as the Merc dealer.
Then it will off for a full service, if I can get it in anywhere before XMAS.

Thanks everyone for your advice, (yes that includes you Noel) lets hope it's not sensors or ECU problem, sounds expensive.