Wisps of blue smoke

[George V]

I'm looking at buying a 1999 Hunter 430. While looking at the boat the owner started the engine for me and the exhaust had some blue smoke. Not a lot, but enough to notice. It's a Yanmar 50hp diesel with 3000 hours. Questions: 1. What does this mean and can I use it without worry. 2. Is it a deal killer? All answers appreciated~!!

 

[Timm R Oday25]

Blue smoke typically indicates sealing loss . Either rings or valves . Not neccessarily a deal killer . An experianced mechanic
would be able to discern the source . If you are in the market for a 43 foot boat ,
I'm quite sure you are going to want to have the engine checked out before you open your checkbook .

 

[JamesG161]

My 1998 H430 has a 50HP Volvo Penta with less hours, but diesel engines are designed for 10,000+ hours

Sounds like it has been idle for a long time.

Jim...

 

[Morgan donor]

Diesels tend to smoke on initial start up. Injector drip or just plain ole unburnt fuel usually presents as white smoke. Could it be mistaken for "blue oil smoke? Sure. Could it be oil smoke? Sure. Take a big ole inhale and smell it. If it smells like a hot rod diesel pick up or when your furnace died as a kid it's probably nothing too serious. Leaky injectors, poor/old/untreated fuel. Check for service records/periodic oil changes. Ask the current owner if he treats his fuel. If no, and he's selling the boat because he doesn't use it enough...a clue. Ask about fuel filter changes. If he has a filter with a clear bowl look at the color. Rose' good / Merlot bad, another clue.
Yanmar's are pretty reliable. Don't be too concerned if he changed the oil. Fuel issues can be repaired but it all costs $ and time.

 

[jssailem]

Welcome George. Congrats on your first post here on SBO.

Smoke on a diesel engine always creates a stir. Probably better for you that the engine started from a cold state. It has been a cold winter. Some sales folk would have warmed the engine before the buyer arrives.

Look to the engine logs for maintenance issues. You are buying a 25 year old engine. A little smoke is not uncommon. A mechanical inspection would be a good idea. If the boat was well maintained and the sails looked new, all the systems were working, no leaks you may have a good boat that you could adjust the price due to the need for mechanical maintenance.

Best of luck.

 

[dLj]

Do you have a surveyor? Have you considered having a diesel mechanic take a look at the engine? Any idea how long it's been since it was run for more than just starting? Have you done a compression test?

Lots of questions.

If the engine has been sitting for awhile it may simply be startup issues that can make the engine smoke more.

Yanmars are very reliable engines. 3000 hours if well maintained is really nothing to worry about.

What more can you tell us about the motor?

dj