Stuart Turner 1.5hp - seized

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Ibut once you've broken the joint there's nothing to stop it coming off.

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Oh the innocence of youth! - or whatever... Stuarts particularly had quite close tolerance between the studs and the head, and it takes very little to cause the studs to seize to the head casting. Then you have mega problems to which as Trouville has found there is no easy solution.

Trying to force the head up over the studs is not usally an option because of the likelihood of damage to the castings, so putting a stud removing tool on each one, and heating the head up as much as possible in the hopes it will expand off the stud enough to allow the stud to rotate may be a way forward - or may leave you in a worse mess when the studs break off.

If the head has lifted a couple of mills, then you might be able to get a saw blade in to cut the studs. Its then a matter of drilling the studs out of the removed head, which is starightforward, and extracting the ends from the block, which can again be - er - fun. It might be that not all the studs are seized, so always start with the ones that look worst.

A right bar steward of a job though....
 
I dident want to have to cut and drill out the studs. But indeed the head stuck!!I would like to get it going again but each time i look at the head stuck i put off the date!

Is there somewhere i could buy a classic engine in working condition? even a dolphin? I never see them for sale?
 
Hmm this is an education. I'll make sure I put plenty of plus gas or equivalent on the studs to make sure they un-seize from the head as best as possible, and I'll give it a try warming it up before removing. How long do you think I can afford to run it for without any cooling water running through it before it starts doing damage?

Thanks again
Ben
 
Stuck head

Old Harry.
Thanks for the complement, but I'm not that young and definitely not innocent.

I can only reiterate that once I had broken the cylinder head to cylinder barrel joint I had no real difficulty sliding the head over the studs. A block of hardwood, a lumphammer and knocking it up and off from alternate sides. I had the engine bolted to my workbech which helped.
In my defence I will say that on two of the studs the nut had seized and the whole stud unscrewed from the crankcase block. At first I thought they were running in drilled holes the full length of the cylinder block. In truth the entire cooling system was solid with baked Firth of Forth silt.

Trouville
You might consider doubling up the nuts and try unscrewing some of the studs from the crankcase. Immersing the engine in a barrel of diesel for a month beforehand might also help.

The bad news is you will probably have the same trouble with the exhaust expansion pot on the side. It too is riddled with cooling galleries which, in my engine at least, needed to be cleaned out with bits of bent wire.
 
Re: Stuck head

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Old Harry.
Thanks for the complement,

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Frame it - they are rare as hens teeth in the OH household!

You were lucky with your engine: It is not uncommon with these engines for the head studs to rust solid to the head casting, particularly if the engine was installed so that water or spray could reach it. Effectively the stud and head rusts into one solid and totally immoveable mass, and things have to be cut, drilled or broken to shift it at all.

Doubling up the nuts is good advice, and standard workshop procedure for removing studs from the block, but when they are badly seized or rusted a proper stud removing tool allows much more torque to be applied. This is a gadget that has a square drive for a socket wrench, and a solidly made cam device that grips the shaft of the stud. The cam ensures that the more pressure that is applied the stronger the grip and has a milled working face that under high pressure will actually cut into and grip the stud to stop the tool slipping.

I have seen a 3/4 inch stud break off using one of these things and excessive leverage - had the stud been heated it would almost certainly have shifted.....

The only draw back is you need enough of the stud exposed to be able to get the tool fully over it.
 
Not a direct analogy, but the British Seagull handbook says that you can run one of those for thirty seconds with no water circulating - they suggest doing this as am emergency measure in the context of reviving a Seagull that has had a salt water bath.

Presumably the bigger mass of a Stuart block would take longer to warm up. I don't know what the effect of running dry is on a Stuart positive displacement water pump - the Seagull has an alloy impeller running with no contact so it's not an issue.
 
Talking of seagulls! Thats another project on winter!! Not long after changing my Stuart turner i arrived in the med. Pumped up my then Black avon and mounted the seagull whic wouldent start. take off sea gull try ashore where it would start first pull???

Remount it start it would run. Later the same day wouldent start,took it ashore started!! Eventualy gave up went to Toulon and bought a secondhand torhatsu? 1HP or 1.5 the seagull must have got sea water in it as a few days later it was seized and has been next to the Stuart ever since.

Is there a way to unseize a small outboard?? Or will the rungs have frozen to the bore??

Later i bought a second hand seagull cheaply £80 with the same problem as mine wouldent always run!! This time i dimanteled the carb and turned the cylinder around, This sea gull starts first pull and wont stop!!! When i come in i have to grab the flywheel eventualy stopping it!!!!
 
I am no Seagull expert...but I know a man who is!

Like many another Seagull owner I am indebted to John Williams who runs:

Saving Old Seagulls

for far more than a spare parts service - endless help, advice and enthusiasm!
 
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Talking of seagulls! the seagull whic wouldent start. take off sea gull try ashore where it would start first pull???

Remount it start it would run. Later the same day wouldent start,took it ashore started!!

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C0ommon problem with the small seagulls, and the cause of many of them being chucked.

The reason? Ridiculously simple. On the dinghy the shaft is submerged too deeply, causing excess back pressure in the exhaust preventing it from starting. Ashore mounted either free air, or in a tank - no back pressure - hey presto off she goes! With Trouvilles, presumably there was just enough power when warmed up to overcome the back pressure, and allow it to restart.

Seagulls were well known as the outboard that would only run in the workshop - never on the boat, for this reason.

Solving it? ahah there's the rub! To start the engine you have to go right to the back of the dinghy - engine leg goes deeper, prevents starting..... You needed a hefty gorilla up the sharp end of the dinghy to allow the engine to start.

No Gorilla - out oars!

(SWMBO reading this over ,my shoulder now objecting to being classed as 'the gorilla' - oh heck!)
 
well well!That i would never have thought of! And yes the one that wouldent start was the smallest and the one i use now on classic boats is much bigger but without clutch!!! I cant think of there power size but there hear ill look tommorow

I have the seagull workshop manual and spares book and such problems arnt mentioned!!

Is there any solution other than starting it out of water? it would be possiable but not easy.

The otherone how can i stop it?? even sliding the choke in only slows it a bit!!!From time to time haveing grabed the flywheel and almost stopping it it bursts back into action which can make life interesting!!

once in porto azzuro she started off i missed the other tenders but turned and caught a line under the shaft and pulled all the smaller boats toghether amazing amount of chaos!!

Worst is comeing back aboard, when she started up id miss my boat bumping down the topsides and have to try again or row the last bit wheni get it to stop!!
 
Hi, on a seagull the throttle cable should be set so that pulling it back back beyond a set point reduces the fuel to the extent that the revs die and the engine stops -simple really. On a seagull it is actually much better to just shut the fuel off and burn off what's in the carb - that way it doesn't leak in the car on the way home!
 
Hi Old Harry - what damage would be done by using a thin chisel to tap into the paper gasket? That would seem to be a simple method? It certainly worked for me in taking off the expansion cover which was also seized?
 
Sorry! having a senior moment here.... assuming we are back to your little Stuart? Which paper gasket? The cylinder head gasket should be copper, possibly even a composite though the manuals are not clear, and memory too far gone. The base of the block has a paper gasket between it and the crankcase, as does the expansion chamber to block joint.

Anyway, the danger of trying to drive a chisel or wedge between into a gasket, is that the steel tool is much harder than the relatively soft iron casting, so the casting is distorted. As the head / block joint has close tolerance machined surfaces, the risk of damage is quite high! There is a good chance too that the quite thin head casting will actually break if you are too enthusiastic with the hammer! (For once, not as per my signature!)

If you are able to get the head shifted this way, it would almost certainly need to be checked and re-machined to get it true again.

The block casting would probably survive, but may need to be machined off to get it smooth again. Any scarring of the machined face will present a weakness which could lead later to gasket leaks and failure.

If you did succeed in getting it to shift this way , make sure you work opposite sides in turn, as if the head becomes tilted and out of line with the studs it will jam even more solid! Even one that is free to move can be quite impossible to lift off if it is not kept square to the block.

And Trouville - yes Jimminy is quite right - the Seagull throttle cable should be set so that with the throttle closed the engine stops altogether. Sounds as though yours is well out of adjustment! Fun isn't it!!! I Well remember that desperate grab for something solid as you came up alongside..... /forums/images/graemlins/ooo.gif followed usually by /forums/images/graemlins/blush.gif
 
Re: Stuck head

Stud removing tools are not expensive - Draper do a perfectly good one, but you may have to order it, as car shops dont seem to stock them. A decent tool shop almost certainly will have them.

Do not confuse them with 'Stud Extractors', which are hardened steel reverse thread taper screws designed to be wound into a hole drilled into the top of the stud to remove it after it has snapped off short in the casting, and which is what most car shops assistants understand as 'stud removers'
 
Just so.

The makers handbook recommends stopping a Seagull by closing the fuel tap. As they rightly say, the practised Seagull owner can judge just the moment to shut the tap so that the engine stops just as the boat comes alongside - its rather fun, actually, and adds to the illusion of stylish competence that some of us (me for one!) cherish so much when messing about in boats.

The snag is that you have to reach round behind the engine to close the tap without either capsizing the dinghy or burning your hand on the hottest part of the block!

Old Harry is right about over-immersion, described by John Williams as Seagull hydrophobia!
 
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