Suzuki DF60 2004 overheating

[Greggie]

Hi,
Have a Crestliner CMV1750 boat with a Suzuki DF60 outboard. Both were build in 2004, bought it in 2010, never used. I used it also only a couple of times a year. Only problem I have is that it overheat when you go higher in the rpm. You go off the throttle, let it run 2 min stationary and the overheating goes away and it’s good to go. After a couple of minutes, the same happens if the Rpm it too high. It has still the 13.5 prop. Went last year to the local dealer, they checked the impeller and they advised me to change the propeller to a 16.5. Does this make sense, or what is the problem

[Murray]

I would change the water pump assembly, Suzuki sells a kit with everything you need. As far as the prop goes that won’t affect the overheating issue, you should be able to troll or run it at WOT and not overheat.

[Greggie]

The Suzuki dealer took it last year all apart and could find nothing. Funny part is that it isn’t really overheating. But it looks like it does. I don’t know..

[Murray]

I don’t know either, you mentioned overheating... You are going to have to be more specific unless your only issue is your prop. At the top of the forum there is an excellent article on engine height and prop selection. I just changed my water pump today, it looked fine but the hole in the gravel from the tell tale moved out about 1 1/2” after the water pump change. The water pump I changed was fine, the new one is better.

[Moonlighter]

If the engine has the original water pump from 2004 or even from 2010 it is well and truly past its use by date and must be replaced. The rubber impeller will have got a set in it, and the symptoms of overheating at speed is typical of that. Even after 2-3 years, a engine that has not been run will need its impeller changed.

These engines have 2 temp alarms, one is when the temp hits a “too hot” level, and the other is what we call a gradient alarm where if the engie temp rises too quickly it will alarm before it gets to the overheated level. Yours may be throwing a gradient alarm.

Any Suzuki mechanic worth his or her salt will hook it up to the diagnostic computer and will see the temp alarms and any other fault codes recorded there.

As Murray said get the full kit and replace it all, not just the impeller.

Now as to the prop - why did the mechanic say it should be replaced?? Get them to explain their reasons to you. Otherwise we have no idea whether the suggestion is sensible or not.