Seized engine (Yanmar SB12) - repair or replace ?

[Heathenly Twins]

I'd say it depends on your intentions. Do you love the boat and intend to keep it forever or are you just doing this because you like fixing things?

I'm not terribly experienced yet but I'm on my third boat and have learned a lot from taking on other people's negligence.

How much is your time worth? What sort of workspace do you have available? You could probably save yourself a lot of hassle by pulling the engine and soaking it in diesel to loosen up everything.

You live in the UK, however, and as people have said, there are a lot of good boats for cheap which are more or less ready to sail. Unless you like fixing up neglected junk, I'd say run away from that boat. The owner undoubtedly left many more surprises. The chainplates, deck fittings and rudder shaft are probably corroded, too.

If you're dead set on keeping the boat then I'd put a new Beta Marine engine in. Cheaper parts which are more readily available and relatively uncomplicated. This is just my opinion but only you can answer the questions.

My current boat was owned by idiots previously and everything needs to be replaced. If I didn't intend to keep the boat forever I'd never have bothered but this type of boat is virtually impossible to find where I live so...

Good luck whatever you decide ✌🏻😀❤

[Squanderbucks]

How many projects do you want to tackle. Almost anything can be done putting enough time and money into it. Do you have the experience and tools to tackle this as a project and how much other stuff will be on the list to get this project useable?
If you can take a project boat and do a little here and now and then get some use out of the boat and enjoy it then start on another project the next season and alternate like this then go for it.

I wish I had a dollar for every project boat I've seen people start on with good intentions and a happy feeling in their heart only to give up a year or so into the project when what looked like a not too long list of things to fix seemed to grow as the work progressed not get shorter - at least at first.

There is an old saying that whatever time you estimate for a job before starting on a boat - Triple it to get close to the actual time you will need.

I own a 1965 boat and have greatly restored and upgraded nearly every aspect of it over the 30 years I have owned (basically only the rudders are original) it and have managed to enjoy using it most every year for boating trips of one type or another. By tackling it it a logical manner and taking relatively small "bites" at a time it can be made to work.

If it will end up consuming all your waking time and spare money you also have to consider what impact it will have on your family time missed. Unless they can see a light at the end of the tunnel and feel they can get back some of your personal time with them using the boat it can become a source of contention that bogs down a "project boat" and leads to abandonment and wasted times and money.

Before you begin Look at this thing as a whole - what are you willing to do yourself and how much will you likely have to have others do for you.

[Squanderbucks]

Ditto Heathenly Twins.

[Compass790]

Originally Posted by gary howe

Hi all, thanks again for all the feedback. I've decided to look at a smaller boat that's less of a project and more sailing. If I get to grips with that and enjoy it I can move onto bigger challenges with confidence that it will be worth while.
Regards
Gary

I think that you have made a wise decision if you are a learner sailor.
I personally think it's good to start learning in small dinghys if you are young & nimble enough. Enjoyed following the thread & glad you posted your decision.
Sailing can be magical.

[Cheechako]

Good looking Yanmar cheap:
https://www.ebay.com/i/353080808688?...EaAtXHEALw_wcB

[smoothpiere]

I had this motor in my Vanderstat Black Soo. It wasn't seized but removal and repair was quoted $2500. You will probably be up for new starter motor, alternator, engine bearings, coupling as well as the internals because it has flooded. That 12 hp model is a beauty. What I did was attach a mount on my transom and put on an 8 hp outboard. A small yacht like that you should sail like a dinghy. On and off moorings, in and out of pens (if you have experience) I was selling my boat and it would not sell with a broken down engine. Incidently I did give away my engine to the local Yanmar bloke who did it up and it ended up in a fishing boat in Fiji still going strong 10 years later.

[MikadoII]

This may not be relevant to Gary's situation but I replaced an SB12 in a 30 ft S&S with a new Yanmar 3YM30 without undue problems. The new engine is smaller, lighter, quieter, starts at a flick and is 30 HP v 12HP. The 80 amp alternator is a lot larger than the old one. The only downside was the cost of the new engine. A farmer friend of mine described the SB12 as a common "Agricultural" engine.

[sailingharry]

Wotname and compass790,


You both commented on aftermarket Yanmar parts. I know you are both on the other side of the world from me (US), but I was wondering if you could elaborate? I have a 1998 4JH2E, and while I don't need anything now, I've not found any aftermarket parts. Thoughts?

[Compass790]

Originally Posted by sailingharry

Wotname and compass790,


You both commented on aftermarket Yanmar parts. I know you are both on the other side of the world from me (US), but I was wondering if you could elaborate? I have a 1998 4JH2E, and while I don't need anything now, I've not found any aftermarket parts. Thoughts?

The only Yanmars that have aftermarket parts AFAIK are engines that have a tractor or industrial engine equivalent.
Yanmar got cunning & built marine specific engines so they can charge 10x the price of an industrial engine part.
I suspect it's a corporate ploy to make not much profit on the engines but a killing on the parts. No evidence for that but Beta parts much cheaper.
So your mission, should you choose to accept it, is to find the industrial equivalent which MAY not exist. I cant help you as I haven't gone down that particular rabbit warren.
Actually you are sorta lucky being a yanmar owner in the USA. In NZ the price is 2x the USA price which is why the local agent doesn't get a cent from me. My vendetta is so important to me I wouldn't buy a boat with a Yanmar that doesn't have a tractor or industrial engine equivalent now.
If repowering I tell my customers to choose a Kubota based engine

[Uncle Bob]

Originally Posted by WillyTheRat

Blah, blah blah blah blah blah blah.

Google Yanmar rebuild kit. Found this:
https://www.fridayparts.com/overhaul...SABEgIxgPD_BwE

But I can get you a rebuilt Yanmar for $237,000.00 with only $75,000 down. Beats all of the other prices listed on the forum.

I know nothing about Yanmar engines, but I can use Google.

Wow, at those prices a real steal.

[Cheechako]

Interesting side note. We befriended a couple on a custom finished home built boat in St Martin. He had installed a 4 cyl Yanmar that he bought in Japan. It may have not originally been a marine model. Big heavy block design. Unlike the high RPM over-rated models , it was very old school. Super smooth and quiet at low rpm and the thing would idle so slow you could hardly hear it!