# What check on diesel that's been sitting for 2-3 years.



## kwaltersmi (Aug 14, 2006)

In our ever sooooo slow quest for our "next boat", we've come across one that we're going to try and visit this week. I'm told she's in good condition (broker speak) but that she's been stored on the hard outside and hasn't been in the water since 2010. Apparently the Yanmar diesel was winterized a couple years ago.

Should I be concerned about the diesel engine after an extended layup? I've never owned/operated a diesel before and am not sure what would be done to ensure she's ready to go if we decided to purchase this boat.

We haven't even seen this boat in person yet, so I'm jumping the gun a bit, but I'm curious if having the engine sit for so long should be a concern.


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## Tim R. (Mar 23, 2003)

An engine sitting without being properly prepped could have some issues. Most people do not winterize their engines to the level that would allow an engine to sit idle for years. Some of the exhaust ports are left open and moisture can get into the cylinders.

First thing I would do is check to see if the engine turns by hand. This should be done with the injectors out so the engine has no chance of accidentally starting.

If you can turn it by hand, get a good maine engine mechanic to check it out. Make sure he knows that the engine sat unused and unprepped for 3 years.


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## TQA (Apr 4, 2009)

Tim R. said:


> First thing I would do is check to see if the engine turns by hand. *This should be done with the injectors out so the engine has no chance of accidentally starting.*
> If you can turn it by hand, get a good maine engine mechanic to check it out. Make sure he knows that the engine sat unused and unprepped for 3 years.


Please do not take the injectors out. The correct way to ensure that a diesel does not start when turned over is to slacken the injector pipe nuts at the injectors. [ This assumes there is no decompressor lever. ]

But if all you are doing is somehow turning the engine through a few degrees it is not going to start.

Pull the dipstick and look at the oil clear is OK black is OK white or grey is not. Smell it, if it smells burnt this is not good.

As others have said if you are not confident with engines get some one who knows about marine diesels to attempt to start it for you. They should check to see if the raw water impellor is in place and if it has been left in fit a new one.


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## Tim R. (Mar 23, 2003)

Sorry, I should have been more specific. I did not mean to imply to actually remove the injectors.


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## lancelot9898 (Dec 30, 2008)

I'm not sure if tapeing the exhaust port is necessary considering that the exhaust goes thru a vetus water lift muffler which has been filled with antifreeze. ?


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## Harborless (Nov 10, 2010)

What kind of diesel is it?


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## Harborless (Nov 10, 2010)

I have a Yanmar YSM8. Its very simple. You have not bought the boat so dont waste your time with all this injector stuff. Tell the broker, not yourself, to start her up- but yes do check oil and transmission lube color and odor before.

She should start rough and blow lots of white out the back. This should clear up after a few minutes. Check the outflow and make sure she is spitting water. Black water means oil is in the system like was the case for mine- it meant the baffle hose was shooting oil to the exaust causing black dirty water that over time would cause black smoke and eventually run away.

If clean water is coming out and oil and tranny lube is good color then rev up and down in neutral. Shift in and out of gear. IF your tied to the dock it wont matter if you drive in to the dock and throttle up near full load- run her full for a few minutes- check out water flow and listen to engine running for any off setting noises which would be internal problems and you SHOULD PASS. IF it sounds good and runs strong in forward and reverse for 20 minutes then idle back down and leave in neutral and then inspect visually the water and fuel pump. If they do not know the last time the impeller or fuel filter were changed no big concern- this can be done yourself easily on Yanmars. 

Idle down to lowest load and check engine mounts. Engine should be virating pretty good knock knock knock this is normal but if mounts are loose this means you will have to take out engine and replace the support beams under the fiber glass (pass on boat) or perhaps just go a bigger gauge moutning bolts and bore deeper down (not so big of a deal)
Shut off engine after 45 minutes running and then inspect hoses- any worn hoses should be replaced bu these are cheap and easy but make sure you make a big stink to lower asking price. make sure not a lot of dust is present around belts which means the belts could be worn (easily replaced) or worse misaligned. If worn replace, if misalinghed I recomend you pass.

Next visually inspect the engine compartment. Is any oil leaking or fuel anywehere? Is the engine hot but not burning? 120 degrees around is normal.
is a stream of water evident from the stuffing box (not engine its self but if stuffing box is leaking AFTER engine is off could mean allignment problems and potential expensive repairs. I recomend you dig further- when was last time stuffing was replaced? This is not big deal- if prop shaft and engine are misaligned this is big deal and you should pass.

If the engine its self runs good, spits clean water, shifts fine, runs under load without weird noises, is held fast to the mounting blocks, and is properly aligned you should not have major concerns. Buy the boat. One thing- If the engine IS vibrating a lot then it could be a fouled prop but since your boat has been on hard you wont need to worry about this unless they have a wrong prop with in proper pitch installed.

If you do buy the boat YOU NEED TO take off the fuel pump and check the impeller visually, take off the fuel pump and inspect/replace the fuel filter, replace the belts, replace any suspicious hoses, and start a log of how many hours you are running on it to keep proper maintenance.

Even if you do get a surveyor this is what they will do. They will not go inside the main engine block or tranny and do anything so SAVE YOUR MONEY AND DO THIS YOURSELF.
If THERE IS a problem inside the engine block dont waste your time- move on. Tranny is not as big a deal they can be replaced by yourself (i did mine) but you will still have to disconnect the engine and remove it from the compartment to get to the tranny which is a lot of work and time so unless you REALLY love the boat just pass- its a buyers market.

This is how you survey your diesel. Now save the $500 bucks and get moving!
Hope this helps.


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## captbillc (Jul 31, 2008)

the yanmar diesels have levers on the top that hold the exhaust valves partly open so the engine can be turned over easy. if you can turn it over ok then it would be safe to crank it with the starter to get oil circulating in the engine before trying to start it . checking the condition of the first.. a lot of water in the crankcase will give the oil a milky look. a small amount will cause water drops in the valve cover and under the oil fill cover, wich it in the valve cover on my yanmar 2GM20F . the f means it is fresh water cooled and has a heat exchanger so i have antifreeze for coolant. i was a diesel mechanic for 30 years before i retired, so if you have any other questions i will answer any i can.


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## kwaltersmi (Aug 14, 2006)

Harborless said:


> What kind of diesel is it?


Yanmar 3GM30F

Thanks everyone, great information!


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## Tim R. (Mar 23, 2003)

captbillc said:


> the yanmar diesels have levers on the top that hold the exhaust valves partly open so the engine can be turned over easy.


Not all Yanmars. The 4JH-2E does not.


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## BarryL (Aug 21, 2003)

Hello,

My second boat had been on the hard for over a year before I bought her. I knew very little about diesels at the time. The broker (who was excellent) told me the engine was in good operating condition, and that it would start and run properly, and that a survey would prove this. He said that it was HIS responsibility to get the engine running correctly. 

Anyway, we agreed on a price, pending survey of course, and the yard dropped the boat in the water and worked on getting the engine going. It took a while as there were a number of 'issues' (the engine water intake was clogged with mud from insects, the batteries were flat, etc.) but eventually the engine fired up and ran. After about 10 minutes it purred right along and the surveyor gave the engine (and the rest of the boat) the thumbs up. 

I had that boat for 3 years and the engine ran flawlessly for the entire time. 

Barry


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## jimgo (Sep 12, 2011)

How old is the engine over all? Does the owner have maintenance records for it? If there's a damping plate, has it been replaced?


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## kwaltersmi (Aug 14, 2006)

jimgo said:


> How old is the engine over all? Does the owner have maintenance records for it? If there's a damping plate, has it been replaced?


The engine is a 1987. I have not seen any records yet and I'm not sure about a damping plate (what is it?).


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## jimgo (Sep 12, 2011)

A damping plate is actually two pieces of metal held together with springs. They look something like this:
GM Chevrolet 454 7 4L Marine Drive Plate Damper 26 Spline Gas Boat Big Block | eBay

The damping plate connects the flywheel to the transmission. As I understand it, as the starter kicks the flywheel over (big, hard shove/jolt), the springs in the damping plate help deaden some of the initial jolt so power is more smoothly/evenly transmitted to the transmission. Mine died on my new-to-me 1980 engine on the 3rd day we owned her (she was being moved by a professional captain). I don't believe it had ever been replaced, and eventually the springs give way out of fatigue. Our damping plate failed back at the end of March. We're still waiting for the repairs to be finished, and the bill is going to be several thousand dollars (we're getting a new transmission, too).

As I understand it, not all diesels have damping plates. They seem like a good idea, but they are yet another part that can fail.


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