Rebuild or re-power? This should help make the decision!

[David W]

We have a 1978 2QM15 in our Crown 34. It's 34 years old, blows some white smoke, has a 'glowplug' to help bring her to life. She's been ultra-reliable but I always wonder what it would take to pull her out and drop in a newer, quieter, more fuel efficient power plant.

I've talked to my local dealer about the Beta engines they carry, highly recommended, cheaper parts etc...

Today, I was looking at their used and rebuilt lists and see among other rebuilt engines, a rebuilt 2QM15 for sale at a breath-taking price of $5,700. (see photo)

I actually don’t know what a new 16hp Beta is worth. Surely it can’t be more than 10% more than this…

 

[woodster]

at that price for a rebuilt 34 year old engine (2qm15)....i would do the beta set up.....the yanmar is old and you may not be able to get parts like new head or manifold if needed down the road....one thing you might look at is finding a 2gm20f or even a 3gm30f used and set it up that way....the bata will be the best choice but a used gm in good shape is ok to ...just my 2cents...

regards

woody

 

[Bill Roosa]

Just how fuel inefficient is the dang thing? 16 HP engines are pretty easy to come by and 5.6k just does not sound right, not at all. My cadi Northstar V-8 only costs 4000 to replace and is like 250 HP

 

[David W]

It's not too bad

Just how fuel inefficient is the dang thing? 16 HP engines are pretty easy to come by and 5.6k just does not sound right, not at all. My cadi Northstar V-8 only costs 4000 to replace and is like 250 HP

It burns about .5 gal/hr with a clean hull, .75 to 1 gal/hr if she's dragging a salad bar through the water.

I was stunned by the price, it has to be a factor of its age and the fact that some parts such as the exhaust manifold are NLA. I recall the dealer telling me a 16 or 20 hp was about $6K in the crate.

 

[David W]

Re: It's not too bad

Ours is going to get a valve adjustment and perhaps either new or serviced injectors. I replaced the exhaust manifold and riser last fall. I managed to catch a lucky break and got the manifold from someone who starved their 2QM of oil or it would have been a long search for a good used manifold.

I have been told that the 2QM series are very heavy duty engines and hold their value well.

 

[NYSail]

The way I look at it is how much do you love and use the boat. Spending a few thousand more to get a brand new engine so you will have no problem getting parts ( if thats an issue) that will last another 35 years is worth it if the boat is what you want for the long term.

I would have my 26 year old 3hm35f rebuilt as the parts are readily available and the engine is great.

Betas I hear are nice.

Good luck

 

[Barnacle Bill]

If she blows white smoke upon start up, that could be steam or an indication that you have a bad head gasket. Just sayin'.

 

[Ken13559]

A new 3YM20 would be in ballpark of AUD$7000. USD$ would be about 3-5% more?

 

[David W]

If she blows white smoke upon start up, that could be steam or an indication that you have a bad head gasket. Just sayin'.

No white on start up, only after a period of running.

Had an excellent chat with my local Yanmar mechanic. His advice was that it was very unlikely to be white smoke from low compression as the 2QM's were not known to lose compression. Their downfall is/was poor maintenance of the exhaust manifold.

I described very carefully what happens and he is almost 100% confident what I am seeing is steam. There is no steam unless there is load and more so when there is more load which he was confident was a result of the engine running more hot as more load is applied.

This makes sense in the context of powering at 5 kts on flat water with a certain amount of steam vs much less steam while motoring and running with the main up with a 6 kt following breeze. Less load running = less work for the engine = less steam.

I did find out that the rebuilt 2QM15 they had was so expensive as it was a full tear down and replacement of all bearings, cylinder liners, etc. and the parts are expensive.

In contrast, a new 21 hp Beta is $7,100.

 

[redhead78]

Are u pricing these with a new trans also???/ Red

 

[David W]

Yep, with a transmission

Are u pricing these with a new trans also???/ Red

Seemed like a good price. Of course that price doesn't include putting it in my boat.

 

[sea_casper]

We have a 1978 2QM15 in our Crown 34. It's 34 years old, blows some white smoke, has a 'glowplug' to help bring her to life. She's been ultra-reliable but I always wonder what it would take to pull her out and drop in a newer, quieter, more fuel efficient power plant.

I've talked to my local dealer about the Beta engines they carry, highly recommended, cheaper parts etc...

Today, I was looking at their used and rebuilt lists and see among other rebuilt engines, a rebuilt 2QM15 for sale at a breath-taking price of $5,700. (see photo)

I actually don’t know what a new 16hp Beta is worth. Surely it can’t be more than 10% more than this…

A new 2YM15 is ~$7000 w/transmission, is much lighter and has a heat-exchanger and separate raw water pump. Removal and installation labor is the unknown value.

 

[jrowan]

Have you asked a Yanmar mechanic how much it would cost to rebuild the engine that you currently have on your boat? It has to be a lot cheaper to rebuild it in place, as there is no additional cost to remove the existing engine, install a new one. Also, many engines are installed in a sailboat before the deck is put in place. It may require substantial work or alteration to get a new motor installed on your boat. You already know that your existing motor fits, right? If your exisiting diesel has been reliable & efficient thus far, then I always recommend a rebuild of what you have over a replacement. Replacement motors are usually called for when the original is rusted out, has had major water flooding damage, etc. Ps. My 5411 engine always produces steam discharge from the exhaust, as all of 'em do. It doesn't harm performance at all. Your engine only needs to be rebuilt if it won't start, is totally unreliable, or is leaking oil to the point of failure. Don't fix it if it ain't broke! It doesn't cost you anything to run your existing engine until its really time to rebuild it. Cheers.

 

[David W]

Have you asked a Yanmar mechanic how much it would cost to rebuild the engine that you currently have on your boat? It has to be a lot cheaper to rebuild it in place, as there is no additional cost to remove the existing engine, install a new one. Also, many engines are installed in a sailboat before the deck is put in place. It may require substantial work or alteration to get a new motor installed on your boat. You already know that your existing motor fits, right? If your exisiting diesel has been reliable & efficient thus far, then I always recommend a rebuild of what you have over a replacement. Replacement motors are usually called for when the original is rusted out, has had major water flooding damage, etc. Ps. My 5411 engine always produces steam discharge from the exhaust, as all of 'em do. It doesn't harm performance at all. Your engine only needs to be rebuilt if it won't start, is totally unreliable, or is leaking oil to the point of failure. Don't fix it if it ain't broke! It doesn't cost you anything to run your existing engine until its really time to rebuild it. Cheers.

I had a great conversation with my local Yanmar & Beta dealer and described what I was experiencing.

Context:
1978 engine, unknown hours
'glow plug' pre-heater installed
reluctant to start without 10-15 secs of pre-heater
blows white something after a period of runnng

My thinking that the glow plug was installed because the engine compression was dropping. So the pre-heat warms the incoming charge, making up for the lost compression on start-up and she fires up. Couple that with the white stuff and I conclude low compression.

My mechanic is almost "100% confident" it is not smoke, it is steam. His rationale?

The 2QM series engines were always hard to start the first time each day so the preheat does not necessarily point to low compression. He said installed many pre-heaters on that series of engine even when they were only a few years old.
Doesn't happen after start up
Only occurs while under load

He asked a important question: after the engine is fully warm and producing whiteness , is there less white smoke/steam if the load is reduced?

In fact yes. We discovered this while motoring and running before about a 6 kt breeze. We were doing about 4kts over the ground against a serious current but the following wind provided a enough push to reduce the load on the engine such that it produce just a whisper of steam.

I did a full flush of the block last year using CLR but was afraid of damaging anything so I diluted the CLR by 50%. I'm going to do it again but perhaps use something more purpose-built.

Long story, short we'll keep the shaking, 2 cylinder hulking mass of cast iron 2QM in place until it truly dies!

 

[jrowan]

Good for you. Get the full life outta her before you consider rebuild or replacement.
Also an eventual short rebuild with honing of the cylinder walls & replacing the piston rings will most certainly bring the old girl back to life again. But it sounds like she's running fine. All of the Universal diesels have glow plugs installed as factory equipment, & most of 'em won't start at all when cold without 30 full seconds of glow plug warm up. All diesel cars also have glowplugs or they wouldn't start during cold winter temps. Most diesels should run for many thosands of hours of use before rebuild is necessary. Cheers.