Dolphin engine rant

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Dougy

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Well I have had nothing but problems since becoming the new owner of this Dolphin engine since April, it has never ran properly for longer than an hour due ti initial fuel problems and now it seems its only firing on one cylinder. I have changed the fuel, 22ltrs of it. the fuel pipe, the plugs and HT leads, the fuel filter, had the carb apart and cleaned kissed and kicked it over the last few months, ran great for a week or so for an hour at a time and now its hardly got any power after a 3 hour run even though I have sparks, After much research and finding similar probs on the net it looks like its low compression, so a time consuming expensive repair to an old smelly petrol inboard is needed, the dam thing doesn't even have an alternator so charging batteries is left to solar and with the summer we are having.........It has gravity fed fuel so that's a problem if its not set up right or heavy seas with little fuel in the tank..it has no neutral, forward back or stop, you have to stop it and restart to go backwards, great in tight harbors!! Nothing but problems!!
I have sailed to IOW and it cut out at the entrance to Yarmouth (bad fuel), had to use a 2hp back up outboard all the way back 7hrs! and recently had to cut a few days short due to engine problems (HT leads), I have had a fuel leak, the carb float stuck and ended up with a couple of gallons of petrol in the bilges, luckily I have packed up smoking, the water pump stopped going round so I had to have that apart re grease etc etc etc, the sea cocks for the water cooling stuck, I took the fuel tank completely out and cleaned it and shook bolts around to try and get rid of the rust inside (this seemed to work at least and I have clean fuel).
I spend 2 hours tinkering with the dammed thing for every 3 hours I sail!! YES this is a sail boat not a motor boat!
So what to do???
I LOVE IT!! I know im mad but I absolutely love the dam thing, so I am going to repair it and keep it.
On a serious note these engines, when running, are brilliant and I haven't found anyone who has had one who says different.
I will rebuild it as much as finances allow, I have all rebuild manuals and instruction booklets from original owner and company dating back to the 70s so if anyone needs any info they cant get from dolphin engines I probably have it and am more than happy to scan and mail to anyone. Likewise anyone whose an expert with 2 stroke 12 hp dolphin engine rebuilds who lives in or near Poole with a full tool kit is more than welcome to get in touch :-)
I have yet to go down and check the compression so its not 100% that it is a major problem yet and I am clinging to the hope that its a loose head bolt or joint or gasket and its sucking air in somewhere. (that's the latest tantalizingly fingers crossed possible cause of my problem that I have received from the net) so off to check that when the sun comes out...if not, its coming out at the end of the season and I will be in Poole repairing, cursing, kicking thumping and drooling over it.
I remember going sailing in shorts and sun cream now its overalls and swarfeega!!
 
Dougy said:
I LOVE IT!! I know im mad but I absolutely love the dam thing, so I am going to repair it and keep it.
On a serious note these engines, when running, are brilliant and I haven't found anyone who has had one who says different.
I will rebuild it as much as finances allow, I have all rebuild manuals and instruction booklets from original owner and company dating back to the 70s so if anyone needs any info they cant get from dolphin engines I probably have it and am more than happy to scan and mail to anyone. Likewise anyone whose an expert with 2 stroke 12 hp dolphin engine rebuilds who lives in or near Poole with a full tool kit is more than welcome to get in touch :-)
Click to expand...

Did you know the company is still in business, selling spares and rebuilt engines?

http://www.dolphinengines.co.uk/
 
I have been on a boat with a Dolphin engine and it was beautifully smooth and quiet, and the stop-restart reversing worked perfectly so I can understand your trying to persist. If yours has a Dynastart you should still get some useful battery charging from it: my old 7 hp Volvo with Dynastart kept a battery up fairly well.
 
Hi jumbleduck
Yes I spoke to Dolphin (very helpful bunch) and it was they who told me to carry out a compression test, which is why I am pretty sure that will be the problem, but straws are to be clutched at...
 
Yes when I first bought the boat I decided to whip it out and get a diesel and everyone I spoke to advised the same BUT after a few hours motoring I was amazed how quiet, powerful and strangely pretty it was and fell instantly in love. I will definitely be keeping it.
Although I do seem to having battery problems, I think two new ones for the start of next season will do the trick. I have also just installed a 20w solar panel which works great..... in sunshine :-)
 
I can understand the fascination of the Dolphin - takes me back to fixing scooters and bikes (most days to keep them running). I ended up convinced that two strokes were manufactured only because they are cheap to build. Their simplicity makes them inefficient but more than halves the number of moving parts. Unfortunately, every engine manufacturer seems to carry the cost reduction too far and they tend to have monkey metal bores which wear out in a couple of years (Like my Lambretta halfway up Beacon Hill). If the bore is fit for purpose - or preferrably a press fit liner - then they should last forever with barely any maintenance. If you combined this with the other thread about electronic ignition, then what's not to like? Kind of suggests that you either go for a complete update and blueprinting or scrap it! Hope everything works out.

Rob.
 
Just as an aside, but is the Dolphin with it's unusual reversing system the engine about which it was said?

"An engine designed by an engineer whose wife had run off with a yachtsman." :D
 
Before you suspect compression it is worth checking the exhaust is clear. The Dolphin injects its cooling water into the back of the exhaust manifold first before it goes round the block, this tends to over cool the manifold & causes a carbon ring to build up at this point. I have seen this reduce the bore of the manifold by a large amount. It will cause low power & the engine will seem to have low compression. Worth a try before tearing the poor thing apart!
 
Emotionally, I agree. Nursing an engine back to life is very satisfying.I used to have a garage full of elderly outboards.

Here's a 'but'.. I now have boring engines. Yanmar inboard (QM 15, so quite elderly) and new old stock Mariner 2hp tender engine.

Both never play up, they just work. (so far!) I like 'boring' when on the water.
 
NickRobinson said:
Emotionally, I agree. Nursing an engine back to life is very satisfying.I used to have a garage full of elderly outboards.

Here's a 'but'.. I now have boring engines. Yanmar inboard (QM 15, so quite elderly) and new old stock Mariner 2hp tender engine.

Both never play up, they just work. (so far!) I like 'boring' when on the water.
Click to expand...
 
rob2 said:
I can understand the fascination of the Dolphin - takes me back to fixing scooters and bikes (most days to keep them running). I ended up convinced that two strokes were manufactured only because they are cheap to build. Their simplicity makes them inefficient but more than halves the number of moving parts. Unfortunately, every engine manufacturer seems to carry the cost reduction too far and they tend to have monkey metal bores which wear out in a couple of years (Like my Lambretta halfway up Beacon Hill). If the bore is fit for purpose - or preferrably a press fit liner - then they should last forever with barely any maintenance. If you combined this with the other thread about electronic ignition, then what's not to like? Kind of suggests that you either go for a complete update and blueprinting or scrap it! Hope everything works out.

Rob.
Click to expand...

Hi Rob, I totally agree and I am pretty sure this will end up a complete rebuild.
 
pcatterall said:
Sounds like a ‘winter project’!! Can you get the engine out and home to your garage?

Rusty tank will only get worse so you may want to consider that as well. ( changing it!!)
You love it !! so persevere!
Click to expand...

The advertising brochure for Dolphin shows a chap carrying two dolphin engines, one under each arm, they are very light and very easy to take out, so it will be in the kitch...garage and I agree the tank is also to be changed to a plastic one although I did toy with the idea of having a replica custom one made.... but not cheap!! There is apparently something you can tip into the tank which then coats it and stops the rust but it is around £40 I believe and not sure how good it is, so although the tank fits lovely and has external filling, I may have to go plastic..
 
Keith 66 said:
Before you suspect compression it is worth checking the exhaust is clear. The Dolphin injects its cooling water into the back of the exhaust manifold first before it goes round the block, this tends to over cool the manifold & causes a carbon ring to build up at this point. I have seen this reduce the bore of the manifold by a large amount. It will cause low power & the engine will seem to have low compression. Worth a try before tearing the poor thing apart!
Click to expand...

Thanks Keith! That is another of those fingers crossed great ideas I need to keep my hopes up that I haven't looked at yet and as soon as the sun comes out ... I will take a look. So it may be the end of the season anyway...
 
It could be worn seals on the crankshaft, drawing in air when warm, or the roller bearings could be shot causing too much movement around the seals. They are easy to dismantle, undo head bolts, lift off flat head, then undo bolts securing the cylinder block. Lift block up leaving the pistons behind. You can then turn engine over using the pistons to feel for any roughness, should be nice and smooth. p.s. the crankshaft is pressed together so its either a return to dolphin job or specialist in two strokes.
 
I had a Dolphin years ago and my main memory of its workings is that it mattered a great deal which plugs you used. Maybe modern versions and modern plugs have changed, but it might be worth seeing if a better plug would help. Good quality oil also affected its use.
 
Stuart Turners were very often problems because of clogged exhausts. I once helped a friend with one in a Macwester 26, 'cook' his exhaust on a beach bonfire in Christchurch to try and burn off the baked in carbon. It worked to an extent but he later took the exhaust piping to work where he was an engineer and had it caustic bath cleaned after which the engine ran just fine. I do also recall with that engine only one type of champion spark plug would work properly too.
 
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