Yanmar 2QM15 woes

[SailboatJimmy]

Greetings to All,

I have a 1980 Hunter 33' I have owned about 10 years, with a Yanmar 2QM15, the motor is getting hard to start when cold, noticed it is smoking lately, (not Camels) and is spitting unburned diesel out the exhaust??? Any thoughts? Appreicate any suggestions.
Sail Boat Jimmy

[jlogan]

Had one of these in a Hunter 33 for several years. Simple little motor, but even they can wear out. Some things to check:

1. what color is the smoke? If its blue, and seems to increase with rpm, then it is likely oil smoke caused by worn rings or cylinder bores, and a rebuild might be in order. If the smoke is black or white, then you have a different problem, white related to head gaskets or unburned fuel, if black, then you are having a problem with too much fuel for the rpm and load you are experiencing at that time.

2. Make sure your intake and exhaust is working ok. The 2QM15 had a foam "filter" in the intake, often this gets old and falls apart and is sucked into the engine or intake and acts as a "choke"..the engine won't work well. The exhaust elbow on this engine has a small passage that over time will clog up cause some symptoms of smoking (black) and overheating sometimes. Sometimes you can clean this elbow after you take it off, but most find it is easier to put a new one on.

3. You may have a bad injector or injector pump. Sometimes an injector can go bad from a little water in the diesel that gets past your filters. This can cause poor running and fuel out the exhaust.

If you would provide more detail about your symptoms: what color smoke, does the engine start better after it is warm, does it overheat or make steam (white) out the exhaust, does it seem to have the power it always had, did these symptoms start suddenly or develop over time, that sort of thing, you could get better answers about what to look for as a problem. Good Luck

[SailboatJimmy]

jlogan,
Thank you for your professional courtesy, I appreicate your insight. I will be heading up to Lake Texoma on Sunday, and will be happy to report back those items you suggested checking on. I have printed your information on this thread and will take it with me. Thank you again.
Hope everyone has a safe, fun and festive Fourth of July.
Sailboat Jimmy

[Chief Engineer]

Look at the injectors first.

[Ex-Calif]

Also think about a better description than simply hard to start when cold.

When Cold - About how long do you have to crank before it fires? Immediately after firing how does it perform? smoke? acceleration? idling OK? Anything unusual from the exhaust? i.e. unburned fuel or water? Is there any oil in the exhaust?

When Hot - Comparison. Same questions.

Oil in the water? Water in the oil?

[SailboatJimmy]

Finally got up to the boat this past weekend, studied the exhaust as I cranked it.
I believe the motor has about 6,500 - 7,000 hours on it, I am told it should go about 10,000 hours, it does have some blown by at the engine oil filler cap on top of the engine. For about the last two years it's little hard to start ( no glow plug to warm it up) when its sat for an extended period, I have taken to given it a very little squirt of starting fluid prior to cranking it up, and it starts right up. I noticed it smokes a black smoke and a large amount of unburned diesel (as well as burned carbon looking gung comes out when it first starts) and continues to comes out of the exhaust as I rev the motor slightly. As it warms up the smoke changes to blue/white smoke. The diesel continues to come out with the cooling water as it exits the exhaust system. I just purchased two new injectors, and any new fuel lines, filters, and washers they still have available. They say some items are out of production. Any ideas as to where 2QM15 parts can be had? Appreicate any insight.
Thanks,
Jim

[Ex-Calif]

2 cents mode - You can start putting new systems parts on it and it will start eating boat dollars. But in reality it sounds like it is getting pretty tired.

You can probably limp it along for quite a while to come doing things you are already doing. Or you can grit your teeth and start planning an overhaul.

[Chief Engineer]

Put the injectors in.

Throw away that can of ether.....When I find it on a customers boat...it goes home with me.

One of the quicker ways to wear out an engine. They become etherholics if you use enuf of it.

[Inlet Marine Services]

A thought, the motor was made in 1977-1979. It might be just tired nd time to repower

[cantxsailor]

It runs but puts lots of black soot out of the exhaust but if I add a few gallons of fresh fuel it cleans right up. I only use about 8gallons a year so it gets stale. My engine too is now 30yrs old but starts and runs very well all things concidered. I do have to keep the prop clean or it will also soot up. Try this site for more Yanmar info.......m

http://www.freeboards.net/?mforum=yanmarhelp

[SailboatJimmy]

Hey now!

Just hung up the phone with my personal mechanic. THERE IS A GOD!!! After my mechanic replaced the two old injectors (est. 25 years old, rebuilt 2-3Xs,) about $86.00 each and about $200.00 worth of all the fuel lines & hoses, and washers/packing, Yanmar fuel filters, Raycor water seperator/filter, new cone shaped air filter and water pump impeller,(basically all the lines from the little clicker pump, to the injectors, my guy is telling me it starts right up, runs like a top, and get this: it doesn't require either to start anymore, and no black smoke or diesel coming out the exhaust!!!! Seems like we over tighten some of the lines a few times and it was sucking air from a number of places, this was confirmed by the little puddle of diesel found in the engine bildge after running in and out of the slip. Thanks to everyone who contributed their ideas on this fourm. Looks like the motor is ready for another 5-10 years.. Like the energerizer bunny! Love those Yanmar diesels!!!!
Thanks again..
Jim

[Chief Engineer]

Now...what you do is get rid of that can of ether and commit this guy's phone number to your memory bank.