diesel motor recommended operating RPMs

[Ctskip]

I have a Universal 5416(16 hp) with 2000 hrs on her.She's original to the boat 1983. The manual says max rpms is 2800. At what rpm should I be motoring out and in with? I use the motor as little as possible, maybe 10 minutes each way.I let her warm(varing the rpms, 800 to 1500) for 10 minutes before leaving. What RPM should I cruise at? Thanks Keep it up, Ctskip

 

[Capt J]

Normally

The engine will cruise at about 80% of max RPM or about 2250 to 2300.

 

[tom]

Just Motored 450 miles

My wife and I just motored up the river from Mobile to the Tennessee river. The engine runs better now than it did at the start. The max rpm is 2500 and we kept it at 1800-2000 for 8-10 hours a day. That's about 80%. If I pushed it harder it overheated after 10-15 minutes plus I didn't go significantly faster. I guess that being ran for a long while burned crud off the injectors and polished up the cylinders etc. It's probably good for your engine to run it until it is good and hot acouple of times a month to drive out moisture.

 

[sailaway78]

Diesel RPM

Diesels do better when run hard. All of them. Most recommend 80%. I normally run mine wide open for about a minute, then cut it back to 75-80%. There will also be a sweet spot in there somewhere, and it will be noticable if you pay attention. Engine will just seem to be a little more quiet, a little less vibration. I was on Tony B's boat a couple of weeks ago, and the sweet spot on his is very noticable. Much more so than on my boat.

 

[Rich Stidger]

My Volvo East Coast Tech rep told me....

to run at WOT minus 400rpm. That would be 2600rpm for me (3000-400).Also, every time you go out, run at WOT for 10 minutes. When I asked why I should do this WOT 10 minute burn, he told me it was for two reasons.First, it cleans the engine and forces the injectors to open their full measure.And second, by doing a WOT for 10 minutes you also verify that the engine will in fact achieve WOT and that there is not an overheat issue when running at max power. He reasoned that if there was an engine issue or a prop issue that prevented the system from reaching WOT, it was better to find out at a time when the conditions did not demand full power.I have performed this action for the last 8 years. I have checked the exhaust elbow several and have negligable build-up. Basically, it works for me.

 

[Honeyman]

CT...

your diesel should last you approx. 10,000 hrs. if you use it properly. "10 minutes each way", isn't proper use. As previous posters have said, you need to run at 75-80% max. rpm most of the time and it takes about 30 min. "each way" to warm up. Worst case, on a lake, you really need to "blow it out" at close to maximum rpms, several times per year. You can run at max. rpms for an hour or two with no problem.

 

[Ctskip]

Thank you all

I guess I have to blow it out, just like in my gas engines. Accelerate hard and black smoke (carbon build up) leaves the cylinders. I guess bacically its the same theory.Thanks to all and hopefully it'll be there when I need it.Thanks again and above all, Keep it up, Ctskip

 

[Big Windy]

RPM

Diesels like to work. I idle out of the cove to the lake, then, when finished sailing coming back, I lower the sails across the lake and run it hard back to the cove.