Outboard RPM Speed

[Karen Ann IV]

Whan I reciently traded my old boat with yamaha 300 engines I was told that I was not running the engines fast enough. I was told I needed to get them up up 4000 to 5000 rpm's more often. What is your history and feeling about this advice.

 

[drbatts]

I agree. Engines are meant to be run.

 

[Hookup1]

My mechanic says carbon buildup on the rings is what kills them. He recommends coming in and running on the pins for a few minutes and to use Ring-Free additive.

 

[luckydude]

+1 for ring free and let them run. It sure seems to me that every boat seems happy at 4400 rpm.

 

[wspitler]

I disagree somewhat. In the days of 2 stroke engines with carbon buildup, that was very true. Todays modern 4 strokes are very similar to automobile engines (albeit in a slightly different environment). They are clean burning, fuel injected, low emissions. In fact, some of the Honda outboards are based on their small car engines. I had 4 stroke F250 Yamahas that I put over 1200 hours on that had no carbon buildup at all and most of their usage was at 1500RPM or less. I never went above 5000 RPM. We don't seem to have the problem with very similar engines used in taxis, etc. The marine environment, IMHO, has little to do with carbon buildup.

 

[seasick]

I agree with wspitler. As long as the boat at WOT runs in the specified rpm range ,other than cleaning the hull, there is no need to run at high revs.
The carbon issue is true for 2 strokes but not four.
With respect to additives, see what the manufacturer recommends.

 

[Fishtales]

I use the RF as well. Run em at 4K - 5K every now and then but not into running em hard for long periods.