theselkie said..
Hi
Does anyone have any knowledge and/or experience with this old diesel dinosaur or the Hydralign Prop?

Powering a 1980 Tasman 26.

theselkie said..
Hi
Does anyone have any knowledge and/or experience with this old diesel dinosaur or the Hydralign Prop?

Powering a 1980 Tasman 26.

The Yanmar has the piston horizontal and parts are hard to come by. Plenty of info at the usual sources. I would not buy a yacht with one.
www.cruisersforum.com/forums/f54/trouble-with-yanmar-ysb8-979.html

The hydralign I would have in a heartbeat.

jbc-engineering.myshopify.com/

I and plenty of others have found the old Yanmar supper reliable.
They have the reputation of being bullet proof

the old yannmars are very reliable and verrrrryyy heavy hydralign props are robust though a little bigger profile most failures with feathering props occur though changing from forward to reverse at to higher revs

I had blowby in the 2003 volvo in my boat.
Why would it stop you from purchasing a boat?
Anyone buying any boat with a motor of that vintage you would be dreaming to not factor in the very real possibility of having to replace soon. Any time you get from an engine of that age needs to be treated as a bonus .

Thanks for your replies.

For better or worse, I've purchased the boat.

Had two mechanics out to look at the engine who were both pleasantly surprised. It starts very easily, sounds good...problem is it's not pushing the boat along very fast and when I open the throttle, leaves a trail of black smoke.

Each mechanic presented two very different diagnoses. One quoted 3.5k to do the work ??.

I've decided to have a go myself at:
Remove and have injector serviced;
Replace exhaust elbow;
Replace exhaust waterlock.

This will be the start.

The Hydralign Prop I'm not too happy with. There is a lot of vibration at low revs and one of the mechanics believed the shaft may be bent.
The engine is mounted forward underneath the v-berth on the Tasman 26, so I kind of feel the extraordinary length of the shaft compromises it further.

The previous owner installed the Hydralign and shaft in the past 18 mths. I'm hoping (wishing) he may still have the old prop and shaft.

Once again, thanks for your help.

theselkie said..
Thanks for your replies.

For better or worse, I've purchased the boat.

Had two mechanics out to look at the engine who were both pleasantly surprised. It starts very easily, sounds good...problem is it's not pushing the boat along very fast and when I open the throttle, leaves a trail of black smoke.

Each mechanic presented two very different diagnoses. One quoted 3.5k to do the work ??.

I've decided to have a go myself at:
Remove and have injector serviced;
Replace exhaust elbow;
Replace exhaust waterlock.

This will be the start.

The Hydralign Prop I'm not too happy with. There is a lot of vibration at low revs and one of the mechanics believed the shaft may be bent.
The engine is mounted forward underneath the v-berth on the Tasman 26, so I kind of feel the extraordinary length of the shaft compromises it further.

The previous owner installed the Hydralign and shaft in the past 18 mths. I'm hoping (wishing) he may still have the old prop and shaft.

Once again, thanks for your help.

I would not do any of those jobs till you have to. If the motor starts easy it has good compression. I would change fuel filters and change the oil. The injectors must be fine if the engine sounds good. I agree with twodogs, check the prop first. Sounds like it has some shell. My folding prop is useless with a couple of shells and the boat speed will drop drastically. The vibration could be simply the shaft anode has come loose or the shell has built up one side more than the other. Take a swim and check first.

Thanks again.

Just learnt the previous owner had her in the travelift, pressure-washed and pitch adjusted on prop a week prior to me buying her.
Could he have adjusted the pitch incorrectly to cause black smoke and little movement???

Agree I'm better off looking out for a replacement engine. Any suggestions? Same mechanic who quoted 3.5k to work on the old one quoted 11.5 to repower with 1gm10...yikes....I only paid 7 for the entire boat!!

Black smoke may be just an issue with slightly blocked/carboned injectors, it may be as simple as putting a bottle of ChemTech diesel additive through the tank before you spend any serious money. Put it through at a very strong rate, then replace filters. This cured a similar problem with a 2.8L diesel 4WD I had.
Greg.

theselkie said..
Thanks again.

Just learnt the previous owner had her in the travelift, pressure-washed and pitch adjusted on prop a week prior to me buying her.
Could he have adjusted the pitch incorrectly to cause black smoke and little movement???

Agree I'm better off looking out for a replacement engine. Any suggestions? Same mechanic who quoted 3.5k to work on the old one quoted 11.5 to repower with 1gm10...yikes....I only paid 7 for the entire boat!!

11.5 is about right. I would always avoid a YSB8/12 but yours seems to be running and sounds like it's basically OK. Black smoke could be from the blades set incorrectly or the bores might be glazed. As a reasonably cheap check I would suggest this snake oil.

costeffective.com.au/product/ftc-decarbonizer/

Made in Queensland. It's expensive snake oil but works a treat.

As I said previously depends on engine bed if you can use the old one it could save a thousand.
Try one of the kabota based they are a bit cheaper.

theselkie said..
Hi guys

I can't express how grateful I am for the knowledge and experience you have all shared with me. Thank you most sincerely.

Update: I ran the motor today for twenty minutes. For the first 10-12, it deposited a good layer of black soot on the surface of the water. After that the water pumped left no soot.

Spoken to the previous owner again tonight who recommends I clean out the waterlock closest to the exhaust outlet. Both mechanics recommended I replace the other waterlock closer to the motor itself. Previous owner also recommends cleaning only (not replacing) exhaust exhaust elbow. On another note, PO assures me the prop shaft is not bent.

Okay, I'm purchasing Ramona's recommended snake-oil tomorrow as a first line of resistance then move on to pulling things apart.

I'm still going to investigate repowering. If not Yanmar, does anyone have any recommendations for new or used?

Once again, I am so grateful for the brains trust here on this forum.

Trace

lot of the older yanmars tended to leave a sooty layer on the surface after startups especially if they had been run a lot and not loaded up.
My father had a lot of these engines in his fishing boats , they were the bees knees of small diesels at the time , had one
over 30 year old when he retired , from memory only issue was carbon build up , was a simple job of removing head and scrapping off the carbon around the valves to get the compression back.

I'm not knowledgeable enough to know whether what I had was an YSB8. All I know is that I had an 8hp Yanmar in the old Supersonic 27 I had.

It was always the case that if you opened the throttle quickly it blew black smoke and kept blowing it. If you eased it up gradually it didn't. So the solution was always to ease back down again and ease it back up.

A mate bought a similar boat and had the same issue.

This was all 30 years ago when the engines were that much newer (but by no means new).

Plus with all my earlier yachts I quickly discovered that any fouling at all made the thing go like a wet week at any revs.

Lots of food for thought. Thanks again everyone.
I'll go for a sail on the weekend to remember why I bought another bloody boat then start trying a few of your excellent suggestions.

theselkie said..
Thanks for your replies.

For better or worse, I've purchased the boat.

Had two mechanics out to look at the engine who were both pleasantly surprised. It starts very easily, sounds good...problem is it's not pushing the boat along very fast and when I open the throttle, leaves a trail of black smoke.

Each mechanic presented two very different diagnoses. One quoted 3.5k to do the work ??.

I've decided to have a go myself at:
Remove and have injector serviced;
Replace exhaust elbow;
Replace exhaust waterlock.

This will be the start.

The Hydralign Prop I'm not too happy with. There is a lot of vibration at low revs and one of the mechanics believed the shaft may be bent.
The engine is mounted forward underneath the v-berth on the Tasman 26, so I kind of feel the extraordinary length of the shaft compromises it further.

The previous owner installed the Hydralign and shaft in the past 18 mths. I'm hoping (wishing) he may still have the old prop and shaft.

Once again, thanks for your help.

20 years ago you could buy a non genuine exhaust elbow for a 1/5 of the price of a yanmar one. I'm not sure if they are still out there but worth googling...

Old thread... hope it all worked out. I had a small Yanmar in my first boat had a 2GM all of 13hp. When the batteries were flat and the alternator pumping out a few amps, it exhibited the same symptoms as yours. Once the batteries were topped up (20 min) she went like a top and would not blow any more smoke. Hope this helps someone.
James