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Seagull.o/b


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Hi Chaps.

Having just got hold of a seagull o/b the one with the clutch I think it's a 6hp model. Now do I add lead additive to the mixture or is it happy with unleaded petrol /oilmix I know that the mix is 3/4 of a pint of oil to 1 gallon of petrol.

 

Cheers Reg

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That's 12:1 mix, seem extremely rich.

 

Do a search on either saving old seagull or saving seagull, it is a site dedicated to saving old seagull ob, the chap who runs it knows everything about the brand.

The mix ratio is perfectly correct as given by Seagull back in the dark ages. But Kam does have a very good point in as much as the origional ratio was for the use of standard SAE 30 motor oil of the 1950's. These days with far far better specific two stroke oils available, considerably less 'MARINE TWO STROKE' oil would be appropriate.

 

Try http://www.seagullparts.co.uk/ for information

 

Mad Mike

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Thanks to you all for your input just had a quick look on the site you mentioned plenty of information which should keep me occupied for an hour or two. The engine had been standing in a garage for a couple of years. done the usual checks. put it in a barrel fired up second pull. compression seemed a bit weak rings might need changing. But if we get any decent weather will give it a good run out on the tyne which is all it might need

 

 

Reg

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weak rings might need changing.

 

Seagulls suffer from a unique problem of cylinder glazing. Due to the high oil/petrol usage and in times past the use of ordinary motor oil.

The cure is to lift the cylinder head (or complete dis-assembly on the old 102 domed headed ones) and with the piston in it's lowest position giving the exposed cylinder walls a real going over with 'coarse' wet and dry wetted with paraffin untill all the brown glazing has gone. DO NOT DE-COKE the piston top all over leave a band of about 1/4" around the edge.

Flush out with paraffin and an air line if pos' and re assemble with a new head gasket.

 

Mad Mike

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BE VERY VERY CAREFUL in removing the head bolts.

 

They are normal steel and the threads go straight into the waterways so often rust up and snap! weep.gif

 

The bolt size is also the old imperial sizes (BSF) so a good set of spanners and sockets are needed.

 

I have been fixing Seagull engines for a number of years and find they are most underated for shear pulling power. Might not get much speed but will cope with most tides.

 

Tip - always keep the fuel tap covered in fuel as the cork stopper dries out and it will leak like mad if allowed to dry out.

 

If you let me know what the serial number of the engine is I should be able to advise you about the engine.

 

Fuel mix should be 10:1 not 12:1 due to the basic design it requires the oil to lubricate everything unless you have fitted a new needle or jet in the carb, Villers needs the needle and Amal carbs use jets. With the conversion the mix is 25:1

This conversion can only be done to post 1967 engines.

 

Unleaded fuel is fine just keep it in an air tight container to stop the fuel going off.

 

Regards

 

Coddy

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Hi Reg

 

Your motor is a Silver Century Plus with clutch, made Oct 1977 - Standard or Short Shaft

 

WSPC = Silver Century Plus with clutch (if it had an L as well it would mean Longshaft)

JJ = October

7 = 1977

 

Gearbox oil should be EP140

 

You could have one of two types of carbs both made by Amal

 

If the float chamber is offset it is the common 2 jet version the other has a round float bowl under the carb body, a Amal 416.

 

Both these carbs can have the Power Jet changed so it can run on 25:1 mix.

 

Points should be set at 20 thou or 0.5mm

Plugs 35 thou or 0.9mm

Use only solid wire plug lead unless contactless points (yours should not have this)

 

Hope the above helps

 

Regards

 

Coddy

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Hi reg

 

The jet to replace is the longer one of the two. Look through the air intake to see both jets. In order to remove the jet you will require a jet removal tool or a pair of long nosed pliers but be carful not to damage the thread on the bottom of the carb body.

 

The Amal Jets are numbered. If it is numbered 45 or 50 it is a 10:1 jet, if it is numbered 40 it is a converted 25:1 jet.

 

I always run the carb dry after a run as it reduces the amount of oily goo left in the carb body if the engine iis not used regularly.

 

Coddy

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