Questions to ask about Cummins 5.9

[Not]

Stepping into the fire a bit here. I’m definitely wet behind the ears when it comes to Cummins knowledge. Still, having read Tony’s posts for years I know I’m in the right place.

We’ve the possibility of picking up a trawler at a very reasonable price. What I know: It’s Cummins 5.9 equipped, early 90’s vintage, naturally aspirated and has about 7500 hours. As of right now, those are the only facts I have in hand on the engine.

I’ve known the current owner for many years, and he’s pretty meticulous about maintenance. Annual haul outs, fresh water flushing, etc. He uses the boat routinely – definitely not something that spends time sitting in the marina, so hopefully common issues related to lack of use will be less likely. He’s owned the vessel since the early 2000’s, and has put the majority of those hours on it and been responsible for its upkeep. While I trust him personally, and he seems quite knowledgeable about all things on the vessel – I’d like to show up better educated, armed with questions and a list of what to look for.

Yes, I’ll get an engine survey if we get that far, but at this point – my goal is to gather enough information to see if this deal is worth pursuing.

Clearly, I’ll want to know exactly what Cummins is in the boat. 6B perhaps, or are there other possibilities that match my limited description above?

He’ll certainly know the history. What questions might I ask? Is there a short list of things I should look for that would be telling from an external inspection or sea trial? I’ll be taking tons of pics, so if there are areas that might be useful to experienced eyes here – I can make sure and post them up in a couple weeks after I’ve gone to see the boat.

I realize the above is pretty generic, but I need to start somewhere. Appreciate any feedback – thanks!

Topic

[Tony Athens]

Maybe some good pics of the engine from all around?

Not many 6B’s out there.

Tony

[Rob Schepis]

In a trawler application yes Id agree that the term bulletproof could be used with confidence……. if all is up to snuff.

Do get the CPL number and serial number.

[Not]

Heh – you beat me to it! I was editing my 6BT description to 6B, hit reply and saw your post. Since I know for certain it’s naturally aspirated and a 5.9, 6B sounds likely as you noted.

From what little I’ve read on the 6B, the common perception seems to be it’s about as bulletproof and simple as one can hope for – assuming proper care, of course. Valid observation?

Thanks much for your detailed comments, Rob. Much appreciated. I’ll follow your advice and report back.

[Rob Schepis]

You’ve got a hands on, meticulous owner of 19 years who uses the boat regularly. Well that is a great recipe if it all turns out as such.

You have a conflict in your post – a 6BT is a turbo engine, not a natural. So it could be the 6B5.9M 115/120hp natural.

This is a non-broker deal, right? another BONUS. Start off by meeting with him and bring your pen and paper (full sheets, no post it notes) and tell him you want the full engine room tour and for him to walk you through and explain everything and everything about upgrades, repairs, preventative maintenance, and the like. Concentrate on the raw water components. Write everything he tells you down, ALL of it. And photograph it all. Photograph everything in the engine room.

Take a photo of the tachometer. As him if it’s been verified with a photo-tach (laser). Ask if he knows the WOT RPM. Ask him what RPM he cruises at and what speed that yields. Ask him if there have been any overheats. Ask if the engine uses any oil and, if so, how much. When you make the appt for your visit tell him you want a cold-start. Video or time it.

Ask what known issues there are with the boat. Every boat has them and if he’s a good guy he’ll explain them. Make notes of those and photos too.

Good luck and report back.

[Author]

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