Pleasure & Pain

[deano]

Hi,
Finally got to use my Featherweight after all the tests in a bucket !
All was going great, having a wonderful time cruising on Ullswater, hoping to make the campsite in good time, then disaster
Now sorry in advance for my lack of engineering know how and jargon but the water stopped flowing out of the little hole on the engine block. I let it cool down and tried again and as before the water flowed at the start, but as the engine heated up it stopped again. I also noticed two stroke leaking from here:

and a little gearbox oil from here:
(Just below the serial No.)

I have flushed the system with a hose and all seems clear. Am I correct in assuming that these small leaks are the cause of the problem, and that I will have to replace the gaskets, and is it a difficult job ?

Here is a clip of my Gull powering a 1978 Mirror Dinghy until it decided to call it a day (great while it lasted) !
The row back with a shoulder injury was not so great but Hey- Ho

https://youtu.be/X9Fcq_y5_2M

[Oyster 49]

I learned to sail in a mirror identical to that

Anyway, it sounds like your water jacket could do with a clean out, take the tank off and apply some gentle heat to each of the 4 head bolts, then carefully take the bolts off. Take your time as they can shear. Once the head is off you can clean out the water passages using a thin screwdriver or the like. Make sure all the debris is removed, and reassemble. You might consider a new head gasket. Don't overtighten the bolts when you reassemble. Run it up again and see how it goes. Water flow does reduce down to nothing at Tick over on these engines so keep the revs up..

Also remember to keep your gearbox oil fresh. The box only holds a small amount on the featherweight. You will see the filler down next to the prop. Change it the oil at least twice each summer and again at the end of the season.

See how it goes and report back.

[pat777]

Some great videography there, looks like you had a nice spot for your adventure, despite the difficulties with the water flow.

John Williams apprentice cutaway model.








When I got my first seagull I had a similar problem, that when I was running the seagull in the barrel it was pumping water no problem with a good flow, but then when I got it out on the boat, it seemed to only flow for a few minutes before stopping altogether. I ended up stripping the outboard down and there was a load of crud blocking the water passages.

There is a also the water flow pipe inside the exhaust that could end up out of place. Perhaps the previous owner had it taken apart and didn't quite get it back in it's place properly. Give us a bit more detail about how long it was running properly for before the water flow stopped.

Here is a link to a guy on youtube with a good breakdown of how the cooling system works on a seagull outboard.



Just noticed Oyster 49 posted, while I was typing, that's the trouble with these long posts, anyway yeh what he said!

[deano]

Thanks for the great replies.
I will have a go at getting the head off this weekend. I have an electric heat gun (the sort of thing that decorators use). Would this be hot enough to heat the bolts up, or would I need a blow torch ?

The Cutaway model is a great resource for a newbie like myself. "So that's how it works"

I would say that the water flowed for about 5 minutes but slowly reduced to a trickle and then nothing. The thing is that in the bucket I didn't really push it as much as I did on the water. As I recall I probably only ran it at half revs with the occasional burst but on the water 2/3 or more.
Oh and just another question: Whats the cylinder head bolt size ?
Cheers
Dean

[pat777]

As I'm sure you are aware, there can be a lot of shaking and vibration when the seagull is running and this can loosen the bits of crud and rust inside the water jacket and cause a blockage. You need the higher revs to keep the water flowing and when idling you will often find the water flow is poor.

You may need to order some parts, new gaskets,bolts etc., probably best to take it apart before ordering parts and see what is needed.

When my father was taking my outboards apart he was using a roofing blow torch to heat up the head studs, not sure if you would get enough heat with the heat gun. If you are not tackling the job until the weekend, it would be no harm getting some "Plus Gas penetrating oil", and spraying the head bolts liberally over the next few days. https://www.amazon.co.uk/English-Abrasi ... B0001P02RK

plus gas.jpg (11.02 KiB) Viewed 2350 times

John Williams advise about head removal on the faq on main SOS site http://www.saving-old-seagulls.co.uk/faq2.html#headleak

My British Seagull runs for 15 minutes then loses power, slowing to a stop. It is not seized.

Sadly this is classic sign of the leaking head gasket, so the head is going to have to come off. I know, it says 'Do not Remove' Yes, it is for a reason, you do not have to de-coke, as we once did with two-strokes, and these screws actually go into the water-jacket, so they can be more than stubborn to remove. A gas blow lamp helps, plus some WD40. They are 5/16 BSF if you need to clean up the threads later..... I now have new S/S head bolts! £2.50 each, same price as rusty ones!

When you have the head off, check there are no faint black marks in the bore... This could be the only sign you might get that the block has cracked, giving the same symptoms. Normally the outside of the block will have gone as well, time to find a new block.... Yes I do have them, for the Forty and the silver Century, but at a price!

Assuming the block is OK, refit with a new head gasket, they are cheap enough, with heat proof silicone sealant, sold in car accessory shops as 'Instant Gasket' or 'No Gasket', orange or black in colour. British Seagull recommended it, as the head and block joints are often not smooth. Tighten bolts finger tight only, leave for 4 hours before finally tightening to 18ft lb, a good hand spanner tightness!

[pat777]

Head removal. (I've not watched this one myself, but going on the quality of his other videos there should be some good pointers on it.)

[tambikeboy]

Might even be a good idea to run the motor for a short spell in the tank providing it's pumping some water..

[deano]

Thanks for all the help
I'm definitely doing an extended test run in the tank once I sort this issue out.
I am going to have to purchase a socket for the the cylinder head studs. Any one know which size fits ?

[pat777]

5/16 BSF ?

...I'm fairly sure they are 5/16 British Standard Fine, guessing on this forum is frowned upon though, so perhaps wait for someone else to confirm.

Here is my source.
viewtopic.php?t=6040

Cylinder head bolts 5/16 BSF

[Charles uk]

I believe John Williams still has some tool kits that have this socket in them with the bonus of the King Dick obstruction spanner 1/4 & 5/16 BSF!

[pat777]

http://www.saving-old-seagulls.co.uk/bu ... spares.htm

Whitworth spanners. That special obstruction spanner, ring spanner and 1/4 BSF socket back in stock!! Sadly though I have no tool rolls left, just the spanners. £12.50 set.

1/4 BSF socket

Is this a typo, should it be 5/16 BSF socket or is the 1/4 BSF socket, useful for something else?

[Charles uk]

There's no fooling you Pat it should read 1/4" Whit or 5/16 BSF.

[Oyster 49]

Two very useful spanners there, well worth having in your toolkit. Anyway hopefully you will be able to remove the cylinder head and clean out the waterways. Wash out all the debris and leave it spotless and it should be fine for ages if you are running in fresh water.

Don't forget to pay attention to your gearbox oil!

[Nudge]

I think Im going to cut one of my spanners and re weld it, so it has a crank like the ones in the pic.
Thanks for posting.