Dad has a 87 Sea Ray 268 with a 260 in it, he left backside of Kelleys island a few eeks ago and overheated, limped boat back to marina letting it cool a few times on the way..was fine all summer until now..never showed signs of an issue

I was not around that weekend, he had the impeller changed at the marina, still overheats... did a T-stat last weekend, still overheats...

Mainly it is good till about 3000 rpm, then it gets hot..220 ish, usually runs 145 or so.

I checked it out after that and took stat out to see if there was anyhting in the system it would flush out, I checked flow at all locations by taking all hoses off one at a time, flow seems OK, not sure how much it should have with an Alpha impeller, with stat out it still gets hot, hoses do not seem to be collapsing, PS cooler is NOT clogged, no oil cooler..maybe water pump? but it was fine one minute then not the next..

I want to do an oil change Friday when I get there, I have heard that once oil overheats it can lead to continued overheating... that is a cheap and easy try, then we are going to remove water pump and check the impeller there...

Anyone have any suggestions? I think I have pretty much covered it but any help of things to look for would be great, I cannot let him spend a ton of money for a Marina to fix it, they will rape him..

I would bet just about anything, that, there is still impeller debris blocking the water passage. Be sure that there are not parts going from the outdrive through the transom. The line is somewhat small and can be blocked easily, due to bends. It's a good idea to change the oil after what had happened, but... that isn't what is causing the problem. Keep flushing....ALL the way back to the drive. You will find the blockage.


Darrell.

bypass the cooler temporarily and install a clear hose from fitting at transom to inlet side of ps cooler on lower port side of engine. then run above 3000 rpm and watch the clear hose - alot of air in hose usually means poor seal under water pump housing to drive gasket. you might find alot of bubbly corrosion on drive mating surface. sand flat and repaint and reseal. no air or a little bit is normal and you must concentrate on engine possibilities. Hope this helps
PS I think the clear hose is 1.5 inch probably 4 feet long

Thanks, I have a few things to look into this weekend..the old im[peller was not blown up, it was fine, but they replaced it anyway.. I have no impeller debris

Full Force - did you ever fix the boat?
maybe you can share the fix so we can all learn

Yes I did.. sorry...

I removed the drive and found that when they did the impeller they did not replace everythign involved, I found the rubber tube coupler melted and only had about a 1/4 inch hole restricting flow, I bought all possible parts and replaced everything in the drive for cooling, all is well!!

thanks - glad u fixed it

Thansk, no problem..