Introduction and is it treatable?

[Charles uk]

Well the "drill spinning" old wives tale has reared it's ugly head again.

I'm still waiting for someone to show me written evidence to prove to me that it's possible re magnetise a Villiers or Wipac flywheel magnet by rotating it past an inactive or midly active ignition coil on a soft iron core.

All the ignitions that have been brought to me with missing magnetism have started once the points have been cleaned & set properly, the coil measured to ensure it's fault free & the condensor & HT lead tested or replaced, so it seems any of these fixes will remagnetise the flywheel as well.

Before I started to write this reply, I spoke to Seagull's last production manager & asked him if he'd ever heard of this happening, his reply was "that's bollocks those magnets were really good", he probably saw more than 500,000 flywheels pass through those gates while he was working there from the early 60's to 1995!

About 6 or 7 years ago I bought an SD with no spark from a boat jumble for £15, I gave it a complete once over to find a teaspoon of iron fillings in the crankcase & almost the same in the cylinder head & a badly scored piston & rod endcap, I'd taken his number as he said he'd another one at home, so I called him to ask about the state of this cylinder, he'd given it about a total of 15 minutes of the drill but without the fuel being turned on.

On this site we've heard of examples of drill caused damage from broken crankshafts, flywheels that won't come off, damaged cylinders & very shiney bearings,
so this site does not recommend this practice!


Please remember the majority of readers of your posts are newbies or guests who might not have your levels of expertise so please add a health warning like " remove sparkplug & leave the fuel turned on after ensuring there is fuel in the tank"!

[charlesp]

This is massively worrying to me; it means that for the first time ever I'm in complete agreement with the other Charles - and that's twice in 24 hours.

I spin magnetos to test for the ability to keep sparking; I do it with a spare crankcase not connected to anything and well lubricated.

Clean points and a good HT lead will sort out an awful lot of problems.

[Daxk]

Thanks Guys, I'm a complete newbie at seagulls and was following advice I read on this Forum.
will have another go at it, Sans Drill, on Sunday and see if I can test the HT lead and points

[pat777]

Well the "drill spinning" old wives tale has reared it's ugly head again.

I'm still waiting for someone to show me written evidence to prove to me that it's possible re magnetise a Villiers or Wipac flywheel magnet by rotating it past an inactive or midly active ignition coil on a soft iron core.

All the ignitions that have been brought to me with missing magnetism have started once the points have been cleaned & set properly, the coil measured to ensure it's fault free & the condensor & HT lead tested or replaced, so it seems any of these fixes will remagnetise the flywheel as well.

Before I started to write this reply, I spoke to Seagull's last production manager & asked him if he'd ever heard of this happening, his reply was "that's bollocks those magnets were really good", he probably saw more than 500,000 flywheels pass through those gates while he was working there from the early 60's to 1995!

About 6 or 7 years ago I bought an SD with no spark from a boat jumble for £15, I gave it a complete once over to find a teaspoon of iron fillings in the crankcase & almost the same in the cylinder head & a badly scored piston & rod endcap, I'd taken his number as he said he'd another one at home, so I called him to ask about the state of this cylinder, he'd given it about a total of 15 minutes of the drill but without the fuel being turned on.

On this site we've heard of examples of drill caused damage from broken crankshafts, flywheels that won't come off, damaged cylinders & very shiney bearings,
so this site does not recommend this practice!


Please remember the majority of readers of your posts are newbies or guests who might not have your levels of expertise so please add a health warning like " remove sparkplug & leave the fuel turned on after ensuring there is fuel in the tank"!

I only tried this drill method as it is mentioned on the main sites faq page: http://saving-old-seagulls.co.uk/faq/faq.htm
Thanks for pointing out the possible side effects of my actions, hopefully I've not done any permanent damage. I only ran the drill for about five minutes, so hopefully I'll get away with it this time.

Cheers Pat



Below is the method as printed on the faq page.

I am getting a spark, but only a very weak one, should I replace the coil?

No, but here is a trick I learnt years ago and thought I had mentioned on these pages already, but no. NOTE, FOR POINTS IGN ONLY. If the spark is weak, it could be that the magnetism in the flywheel is low. You can get flywheels 're-magnetised', at a cost, if you can find someone who has the kit. But first try this:
Spin the engine up with an electric drill! First remove the plug, then fit a socket to the flywheel nut and a drill to a socket set extension. I use a rechargeable electric drill, but any will do. (reduce the friction, squirt a little oil into the bore and carb, to lubricate the motor.)
Spin the motor up, I recon I get to 1500 revs on my drill, maybe a bit less with all the friction, but do that for 5 minutes. Then reconnect plug and lead and look at the spark.... As if by magic it will have increased.
The physicist out there will tell me how, something do with EMF I am sure, all I know is, it works? Try it and see.

Below is the answer! I'm indebted to Fred Holmwood for troubling to tell me why it works, thanks Fred.

The re-magnetising works thus:

The principle of a magneto is that you have two closely wound coils, the primary (low voltage) and the secondary (high voltage)

The flywheel spinning round passes magnets close to the coil core (soft iron) and induces a small voltage, I don't know what in the case of a British Seagull but probably around six volts, this voltage causes current to flow through the contacts to earth and back into the other end of the primary coil. This creates a magnetic field around the coil.

On the contacts opening the current ceases and the magnetic field, caused by the current, collapses.

This collapsing field induces a voltage in the secondary coil which is in the order of several thousands of volts, you have a spark!

When the flywheel magnets become weak through lack of use or knocks you are unable to pull the cord fast enough to produce a voltage in the primary.

If you then apply a drive which is faster rotation the weak residual magnetism induces a weak voltage which in turn induces a small magnetic field the combination of residual and induced produces a larger voltage which induces a larger voltage which in turn induces a slightly larger magnetic field the combination of residual and induced, slightly larger, produces a larger voltage and so on until the unit is running at saturation level, you can now produce a spark!!

Having said that the first move must be to clean the contacts in order to allow the first very weak current to flow without undue resistance!

If you ever come across one that does not respond it probably means that the flywheel magnets are totally devoid of any magnetic field, this could be rectified by passing a small external current through the primary winding, but this isn't as simple as it sounds as you need to know what current to apply and each magnet in the flywheel needs stimulating!

In practice a lantern battery from earth to the coil side of the contact breaker, points open, for a second or two only would probably induce sufficient to get you going again.

Hope I have kept it understandable!!

Regards

Fred Holmwood



Yes this trick does work, here is a letter from a happy British Seaguller to underline it.....

Hi, My name is John Russouw I live in Cape Town, South Africa. My dad recently got his hands on a old seagull (engine no THC 347 L5). I am not sure, but according to your charts it should be a 102 Plus long shaft model, but I stand corrected. We got the engine from a fisherman in Betty's Bay. He told us that he got the engine from another guy and that it hasn't ran in years, but if we got it going we could have it for a R1000. So we took it home and spent hours trying to get the thing to start. We cleaned her up drained the fuel tank cleaned the carburetor out, replaced the spark plug, still nothing. Then we realized that there was no spark. So we automatically assumed that the coil or the condenser had packed up. So we decided to replace the coil and condenser, but before we done that, I suggested we surf the net to get some advice. That's when I stumbled on to your website and thank goodness I did. I read the article about recharging the coil, by spinning the engine with a drill. We had nothing to loose so we tried it. I ran the drill for about 4 mins. We were astonished when the old seagull sprung to life after only one pull of the cord. Me and my dad were so happy we ran to the bar fridge to open up a cold beer to celebrate our success. I'd just like to commend you on a excellent web site. Thanks to your information our seagull is purring like a kitten again

Another British Seagull flies again!

[pat777]

Pat triple 7, I ended up with a palletising crowd from the UK which gave me superb service.Seller was kind enough to strap both to a small pallet and I declared Engines as spare parts rather than outboard motors and dropped the price to 60 Euro for both on a pallet,

€60 seems a reasonable price for delivery all right. Were you waiting long for them to arrive? Did they price it by weight or by the size of the pallet? I suppose it would have cost nearly as much to get one seagull delivered. So probably better to look out for sellers who are selling a couple of outboards in the one auction. Are you saying it would have cost more if you had declared them as outboard motors or would the company have refused to deliver them because of fuel/oil spillage risk? Thanks for letting me know, it's good to have a rough idea of what I might expect to pay if I make an ebay purchase.

Cheers Pat

[Niander101]

Having the piston at BDC is recommended to reduce the sideways movement of the connecting rod and the big end.

How does that work then ?
the big end always stays the same distance from piston where ever the piston is
so tell me how it works?

Do the resident experts follow this advice?

[Charles uk]

Thanks for pointing out those items in the FAQs, I thought they had been deleted some time ago.

During our researches into Seagull technology during the early days of this site, I managed to locate & meet Wipac's chief design engineer from the period that Seagull were using Wipac ignitions.
I phoned him this morning to ask his views on the de/re magnetise question.

Loosing any magnet strength was never a problem for any of the Wipac flywheels as the Magnets used were made from Alnico .


"Alnico is an acronym referring to a family of iron alloys which in addition to iron are composed primarily of aluminium (Al), nickel (Ni) and cobalt (Co), hence al-ni-co. They also include copper, and sometimes titanium. Alnico alloys are ferromagnetic, with a high coercivity (resistance to loss of magnetism) and are used to make permanent magnets. Before the development of rare earth magnets in the 1970s, they were the strongest type of magnet. Other trade names for alloys in this family are: Alni, Alcomax, Hycomax, Columax, and Ticonal.

The composition of alnico alloys is typically 8–12% Al, 15–26% Ni, 5–24% Co, up to 6% Cu, up to 1% Ti, and the balance is Fe. The development of alnico began in 1931, when T. Mishima in Japan discovered that an alloy of iron, nickel, and aluminum had a coercivity of 400 oersted (Oe) (32 kA/m), double that of the best magnet steels of the time.

Alnico alloys make strong permanent magnets, and can be magnetized to produce strong magnetic fields. Of the more commonly available magnets, only rare-earth magnets such as neodymium and samarium-cobalt are stronger. Alnico magnets produce magnetic field strength at their poles as high as 1500 gauss (0.15 tesla), or about 3000 times the strength of Earth's magnetic field. Some brands of alnico are isotropic and can be efficiently magnetized in any direction. Other types, such as alnico 5 and alnico 8, are anisotropic, with each having a preferred direction of magnetization, or orientation. Anisotropic alloys generally have greater magnetic capacity in a preferred orientation than isotropic types. Alnico's remanence (Br) may exceed 12,000 G (1.2 T), its coercivity (Hc) can be up to 1000 oersted (80 kA/m), its energy product ((BH)max) can be up to 5.5 MG·Oe (44 T·A/m). This means alnico can produce a strong magnetic flux in closed magnetic circuit, but has relatively small resistance against demagnetization.

Alnico alloys have some of the highest Curie temperatures of any magnetic material, around 800 °C (1,470 °F), although the maximum working temperature is normally limited to around 538 °C (1,000 °F). They are the only magnets that have useful magnetism even when heated red-hot. This property, as well as its brittleness and high melting point, is the result of the strong tendency toward order due to intermetallic bonding between aluminium and its other constituents. They are also one of the most stable magnets if they are handled properly. Alnico magnets are electrically conductive, unlike ceramic magnets.

As of 2008, Alnico magnets cost about $44/kg ($20/pound) or $4.30/BHmax".

So high temperatures can be ruled out as a method of loosing magnetism as the flywheels melt at a lower temperature & heavy impacts can also be ruled out as the flywheel body is made from a Marzac type material that would fracture before any loss of magnetic strength.

And as for remagnetising, need I go on any more?

[Daxk]

Thanks Pat777, Boa worked a treat.

[Daxk]

I spoke to John about this briefly today, he suggested that a quick way to test the magnets was to hold a screwdriver or small spanner close to the flywheel, my WSPCL stuck the older Century (CPL)did not..

[chris]

I am considering defeat after all the brits wallopped us in the olympics, the last no sparking old outboard I got going was from cleaning the electrics points plug etc, and no spinning

[Daxk]

OK, on my silver Century with wipac 2 ignition,Points are clean and set at 20 thou, new sparkplug, I have circuit from the closed points to the plug, but still no spark,any idea what resistance the HT lead should have and how can I check if the Coil is working?

[Daxk]

I know its a stupid question, but at combustion, (points closed) where is the piston?

[Hugz]

Between 18 and 22 degrees BTDC (before top dead centre).

[Daxk]

thanks, when i look down the barrel,when the points are closed, I would expect the Piston to be near the end of its compression,its not, its only just started the compression stroke, I know that does not affect the lack of spark,just wondered as I have no knowledge of two stroke engines

[Hugz]

I'm a bit rusty on ignition systems but I think the points are closed for the majority of the revolution and then open for a few degrees (is this the dwell angle?) and it is when they close initially that that is the point that the plug sparks.

Flywheel in correct possy? Forty's on the starboard side and centuries (and 102's) on the port.