Mercruiser overheating

[jordale]

This is a rebuilt 1989 140 tha

This is a rebuilt 1989 140 that has been well maintained. When run at 5knts or better there is no problem with overheating. Problem arises at trolling speeds (2 to 3knts) and overheats to the start of the red line on gauge. Any help would be appreciated as I got the boat for fishing and yesterday was the first time I'd been fishing with it. Thanks

 

[Bt Doctur]

impeller was replaced when?
m

impeller was replaced when?
manifold and riser?

 

[jordale]

I do not know when the impelle

I do not know when the impeller was last changed but will find out today. The manifold and riser were new in Nov. of 2009. Thanks

 

[jordale]

Correction on manifold and ris

Correction on manifold and riser. Should be Nov. 2007.Sorry

 

[Bt Doctur]

"on average ,impellers are rep

"on average ,impellers are replaced every 2 years regardless of hours or unless damaged(sand, plastic,seaweed,etc)"