Saving Old Seagulls

I have a complete and functioning Forty Plus, and want to strip and repaint the fuel tank. I have a new decal for it. It is solidly jammed on to the motor, any ideas as to how to remove it, without damaging the tank or the mounting points? I have the proper Whitworth spanners, and the nuts and washers are off. So, now what? Many thanks for any help. David.

Take it slowly and gently. Have you tried any penetrating oil [like PB Blaster] between the head and tank? Nuts back on to tank studs till flush with ends of studs, tap lightly on nuts with hammer? Richard # US 10 paint scraper from Can Tire paint section is very strong and has a very finely tapered long end, try gently prying between tank and head with that. They are under $10 and have innumerable uses, accept no substitute. If you happen to have a beekeeper friend they may have one.
Once you get it off you may want cut some gaskets to fit between the tank and head when you reassemble it.

Put your Seagull back into your test tank & make it ready to run.

Undo the 2 tank retaining nuts so there is a 1/16" between them & the head.

Start the engine.

The tank should vibrate loose.

It will be held in position by aluminium oxide which in a confined space works better than all of Loctite's product range.

Thanks, Phil and Charles. I was a beekeeper, so have what I believe you are referring to as a "Hive Tool" in that trade. Not tried it yet,. I made a wedge from some hardwood, and tried that, as I am a bit nervous using metal wedge, for fear of breaking off the support "tangs" Tried the nut loosened and being hit. I will try penetrating oil +++ over a few days, and then try running around with the retaining nuts loosened. I think I'll take a trollng rod, the salmon are in...... Will let you know how I get on. Thanks again, David.

I have discovered the salmon are now 100k. up the coast, so will try the motor in the test tank. I there any problem in popping off the prop, to reduce splashing and water loss, such as being bad for the motor to run without any resistance? David

No, taking off the prop is a wise move, as the cavitation and aeration caused by the props motions can severely restric the ability of the water pump to pump enough water to keep the motor cool.

Taking the prop off to run a motor in a test tank is a sensible precaution and will not hurt the motor - but beware that without the load it will be able to rev much higher, so be sure not to over-rev it which could be equally bad.

Well thanks to everybody who's helping me. I ran the motor, (starts first go every time, but then one would expect nothing less from a Seagull) and ran it for a good half-hour, but the tank remains stuck fast. I have not located my hive tool, and when I do, I will try that, gently. I noticed that black oil was dribbling down the exhaust pipe from where it joins the block. Is this standard? (I last drove a Seagull when I was 10 (1952) so I wasn't likely to notice that sort of thing!) Or does it point to a problem, and if so, is there a fix? I would rather it didn't happen, for it inevitably will get into the lake/river/sea, or wherever I am, and I don't want to pollute. Does anyone have an answer to that? Once again, thanks to all who are helping, David.

The black oil drip is quite normal. If its a 1968 or later motor it can be converted to 25:1 gas oil mix. The earlier motors may be safe to run on 16:1 with the carb needle adjustment, especially if the motor only gets infrequent use. [ max. 3 turns down from flush]

You could also go to a biodegradable TCW 3 oil. Many Seagull owners run the motors way too rich, check the plug after running, it should not be black and oily. Adjust [Villiers? carb] accordingly, screw needle down for leaner mix. It may take a little running to remove all the excess black drip.

Thanks, Phil, I have already converted to 25:1. Even so, I think I rather over-oiled the petrol this time. I really needed to know if this indicated some serious underlying problem or not. I'm glad it doesn't. I will keep you posted. David.