Edgar wrote:
"Ian Malcolm" wrote:
The best seagull forums are at http://www.saving-old-seagulls.co.uk/
Goto the 'Guest Pages'. If you have any servicing to do or operational
questions - just ask over there.


That is all good stuff but you hardly need the instruction book for these
simple motors. I have had long experience with them and my Century Plus is
50 years old and still good for another 50 as they are very much
over-engineered by modern standards and will accept a lot of abuse and still
run.
The older Seagulls, 40 and 100 series at least, have one great advantage
over modern engines in that the water pump impeller is not made of rubber so
you can clamp them to a bench and run them up dry for a minute or so ashore
and then you know they will start without hassle when you put them on your
boat.
Non contact centrifugal impeller. If you are tank tesing they wont pump
water unless you take the prop off. DONT idle slower than it will pump
*some* water at.
Here is all you really need to know:-
-Use basic 2-stroke oil, not the high tech stuff they use in modern
chainsaws etc.

ANY TCW I II OR III 2 stroke oil even if its fancy stuff or if you have
nothing better SAE30 single grade non-synthetic non-detergent engine
oil. As Edgar said, NOT the oil for air cooled engines.
Seagull recommend a 10:1 mix but if you use this on an engine
that is well run in you will have trouble with plug oiling and lose even
more of the oil into the environment.
Problem is the other way round, early seagulls and very worn ones *NEED*
10:1 to seel the crankcase bearings and get enough compression.
I run mine on 15:1 and it is OK.
*most* seagulls can be converted/may allready have been converted to
25:1 for less smoke but possibly more rust ;-(. *most* engines can be
converted to 16:1 just by carb adjustments. Anyrthing that says 25:1 on
the tank, use 25:1. All others, expect to start off with 10:1 then with
the assistance of the forums, get it down to a reasonable mix. WARNING
altering the oil ratio affects the mixture and can cause the engine to
run lean. DONT run a seagull lean with a heavy load
-Oil in the gearbox must be SAE 140 or thicker, as long as it will still be
pourable (i.e. not a grease). The gearbox has no oil seal and the thick oil
leaks only very slowly through the clearances.
There is an oil 'seal' on the prop shaft thats just a rubber washer in a
recess in the gearbox casting behind the brass bush pinned to the
propshaft behind the prop. Its mostly just to keep grit out. If its too
badly chewed up, the engine ****es oil. If its replaced with a flat
face V seal running against the face of the rear shaft bearing the
gearbox will hold oil to the correct level with very little
contamination for several seasons. Later seagulls have proper oil seals
and use streight SAE90. If the seals are damaged substitute SAE140.
Dont use multigrade. The SAE140 oil is most usually used in old tractors.


The instruction book says "a
certain amount of water in the box doesn't matter" and you will find that
the oil becomes a yellowish emulsion of oil and water. I have never seen a
Seagull where this did not happen and the loadings are so low they run
happily on it. I have never known one that needed new gears from wear .so
the cost of new gears is not a problem.
Geears only die due to corrosion, If too much oil has escaped, the
emulsion breaks down and the gears get exposed to raw seawater. They
then rapidly rust and the housing also gets badly corroded. Also if the
engine is stored for a long time, you can have problems (easily avoided
by running the engine for 1 minute every month or two to keep the oil
and water mixed) or if some idiot has filled the box with grease. All
it takes is unscrew the oil plug a couple times a season with the prop
downwards and then lift the engine towards vertical to check the oil is
up to the minimum level. Put the oil plug back before more than a trace
escapes. The gearbox fill level is level with the bottom side of the
filler hole with the engine vertical. Slight overfilling doesnt hurt
but Segull warn aganst overfilling.

-Spark plugs may be a problem as 18mm ones are hard to find. I have a little
hoard of old ones as they do have the advantage that they can be dismantled
for thorough cleaning so last a very long time. The recommended plug is
Lodge C1 (H1 for hard service) or Champion 8com. There may be some modern
equivalents made for vintage engines but I have no information on this.
the Champion 8COM is long discontinued and are rare and valuable if in
good condition. Champion D16 is the (more) modern equivalent or NGK A6


Recommended gap .012/.015"
The book says .020" and if the ignition system is in good contition and
the flywheel magnets are good, there should be no need to reduce this.
Difficult to start engines *may* respond well to reducing the gap to the
range stated by Edgar

-You need to carry a plug spanner, a screwdriver and,if you have the old
Villiers carburetter, a precision spanner ('King Dick' type) for unscrewing
the jet if it gets blocked. With these three tools and a spare plug you can
be sure of getting the motor going again_in the boat_ in the unlikely event
that it stops.

Add a small adjustable spanner to tighten loose nuts, and a spare drive
spring and split pin and you can get it going as long as nothing
critical has dropped off and sunk as happened to me 18 months ago :-( I
ended up with a Red Bull can instead of a float chamber (the float
floated so I recovered that) to get me back to my mooring!. A small can
of WD40 and some paper towels in a ziplok bag are also worth carrying.

Happy Seagulling.


--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
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'Stingo' Albacore #1554 - 15' Early 60's, Uffa Fox designed,
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