The short answer is... yes it can...
When I worked as service manager for a charter company, we had a half dozen J-105s with cute little 2 cylinder Yanmars. They were all set up with the "class legal" folding prop. This prop was much too steeply pitched for the engine, and resulted in the engine running way below its rated rpm at full throttle. And being J-105 sailors, they never did nothing at less than full throttle!
The result was the exhaust elbows were hopelessly clogged with soot and coke in 18 to 24 months of operation. We kept these elbows as stocked spare parts!
One of the first symptoms, (if you missed the black smoke) was over heating as the water passages were restricted.
Royal Island Harbor, Bahamas
---In amelyachtowners@..., <sailw32@...> wrote :
I think my boat has been running hot for for a couple of years . I just ran it for about 45 minutes after launching and it ran much cooler than previously. The only thing I have done , is that I cleaned the exhaust elbow, it was not that bad. However I also reamed out the channel that I believe water passes through. My question... If that channel is partially blocked would that result in the engine runner hotter.