Little Forty

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flyguy
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Re: Little Forty

Post by flyguy »

I've got the multimeter and have checked some of the connections (I bet I have missed something)
First the HT lead. pointer goes to the other end of the scale. so that looks good I think
From the wire between the coil and the points unit. pointer goes to the other end of the scale. so good I think
But from where the HT lead would connect to the coil and the other end to the wire going to the points.nothing. so am I right to assume the coil is indeed dead?
here is a photo of where I mean, in this photo the black negitive lead is touching the wire from the coil (in this pic it looks like it is touching the lug, it isn't)
Image
1965 40 - 1990 55 - 1954 - Little Forty -1986 EF
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Hugz
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Re: Little Forty

Post by Hugz »

I'm an electrical fitter/mechanic so I know squat ha ha.... Yep just checked a good one and get the same reading as yours. Switched the meter reading to X1K scale and needle goes 3/4 of the way across 8) If no movement on that scale then it is terminally deceased.

E&OE
I should have that on my signature.
Keith.P
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Re: Little Forty

Post by Keith.P »

The coil Just two coil windings, primary winding a thick wire is from the points connection and earth, the secondary winding is from HT plug connection to earth.
The secondary is the usual suspect, as its a very thin wire, this is tested from the HT plug connection and earth.
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flyguy
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Re: Little Forty

Post by flyguy »

Hugz wrote:I'm an electrical fitter/mechanic so I know squat ha ha.... Yep just checked a good one and get the same reading as yours. Switched the meter reading to X1K scale and needle goes 3/4 of the way across 8) If no movement on that scale then it is terminally deceased.

E&OE
I should have that on my signature.
]

no reading anywhere with X1K selected Hugz
I am going to change my signature to BTW I am a complete idiot 8)

Keith.P wrote:The coil Just two coil windings, primary winding a thick wire is from the points connection and earth, the secondary winding is from HT plug connection to earth.
The secondary is the usual suspect, as its a very thin wire, this is tested from the HT plug connection and earth.
Hi again I heard that on the video link Keith but as I have no understanding of what a coil does or how it is made I didn't know what he was saying :shock:
does this mean inside the coil it has 2 different windings, one thick wire and one fine wire, the thick one ( aagh that's me :lol: ) is attached to the wire going to the points and the fine wire is attached to HT connection
1965 40 - 1990 55 - 1954 - Little Forty -1986 EF
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flyguy
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Re: Little Forty

Post by flyguy »

flyguy wrote:
Hugz wrote:I'm an electrical fitter/mechanic so I know squat ha ha.... Yep just checked a good one and get the same reading as yours. Switched the meter reading to X1K scale and needle goes 3/4 of the way across 8) If no movement on that scale then it is terminally deceased.

E&OE
I should have that on my signature.
]

no reading anywhere with X1K selected Hugz
I am going to change my signature to BTW I am a complete idiot 8)

Keith.P wrote:The coil Just two coil windings, primary winding a thick wire is from the points connection and earth, the secondary winding is from HT plug connection to earth.
The secondary is the usual suspect, as its a very thin wire, this is tested from the HT plug connection and earth.
Hi again I heard that on the video link Keith but as I have no understanding of what a coil does or how it is made I didn't know what he was saying :shock:
does this mean inside the coil it has 2 different windings, one thick wire and one fine wire, the thick one ( aagh that's me :lol: ) is attached to the wire going to the points and the fine wire is attached to HT connection
no reading attaching meter to HT connection and the baseplate earth
1965 40 - 1990 55 - 1954 - Little Forty -1986 EF
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Hugz
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Re: Little Forty

Post by Hugz »

Yes. That is correct. The coil/s do/es 2 jobs. One if you pass a magnet across a coil of wire it produces a charge (emf, electrical motive force) which then goes to the points and condensor/capacitor which damn the charge and then let it rip back at the coils to produce the spark at the correct time to ignite the petrol vapour. Secondly the coils act a voltage multiplier. A reverse transformer if you will. Ie if you put 6 volts through a coil of wire with 100 rings and then you wrap another coil of rings say 1000 rings you will increase the voltage 10 times to 600 volts that comes out of the 1000 rings. The positioning of the magnets and the opening of the points enable these two functions to happen at different times in a flywheel revolution. I think they are very clever indeed! Imagine if we replaced the magnets with the mighty powerful rare earth magnets....mega spark. The racing boys can consider it!

Spark plug voltage is about 20,000 volts. If you need a hit, lick your finger and touch the plug when the motor is running... it is exhilarating but it is addictive :evil:

Definitely E&OE in this post..
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flyguy
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Re: Little Forty

Post by flyguy »

I'm going to give 20,000 volts a miss thanks :lol:
right so I need a new or at least a working coil
1965 40 - 1990 55 - 1954 - Little Forty -1986 EF
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flyguy
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Re: Little Forty

Post by flyguy »

I have had a look round but I cannot see anything that shows how to remove a jammed air inlet compensator on the Carb.
Image
I know they screw on and I guess they corrode but what could I try to remove it, or should I just not mess with it?
so far I've tried WD40 and a bit of muscle it won't budge
1965 40 - 1990 55 - 1954 - Little Forty -1986 EF
tambikeboy
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Re: Little Forty

Post by tambikeboy »

Mole grips or a vice but be carefull there very easily marked. ...
Roll me up and smoke me when I die
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Oyster 49
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Re: Little Forty

Post by Oyster 49 »

There is no real reason to take it off, I'd probably leave it be. The inside can be cleaned with paraffin, but if you really want to remove it then a pair of large grips with a cloth wrapped around should do it.
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Charles uk
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Re: Little Forty

Post by Charles uk »

I'm not sure how Seagull stopped them vibrating off, but I would guess something akin to Loctite, I've managed to remove them with the assistance of some light heating (Loctite lets go at circa 130 degrees C) & a welders glove, there are no prizes for setting your carb on fire, they're made from nickel plated brass & are no longer available, so don't destroy it by being too heavy handed!
Make it idiot proof and someone will make a better idiot.
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flyguy
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Re: Little Forty

Post by flyguy »

Great advice as usual thanks, I was thinking of one of those rubber grip things that can be bought to remove jar lids but I'm going to leave it as it is, I'm sure I would only damage it. plus one more job off the to do list
I intend to work on the remaining rust and replace the gearbox oil, shine up all the brass and fill the tank with caustic soda, I have decided that as the tank still has a lot of the original decal I won't strip it and repaint, I can see me getting this running very soon
Thanks for everyone's help, you are amazing
1965 40 - 1990 55 - 1954 - Little Forty -1986 EF
Keith.P
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Re: Little Forty

Post by Keith.P »

I was thinking of one of those rubber grip things that can be bought to remove jar lids
Never come across one of them before, is it a device for old people, you got one Charles? :lol:
I have seen one or two chewed up ones in the past, grips are the usual suspect.
tambikeboy
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Re: Little Forty

Post by tambikeboy »

was thinking of one of those rubber grip things ....had a look in the truckie toolbox no rubber grip things only zip ties and duct tape. ..mental :lol:
Roll me up and smoke me when I die
Regret is just a memory written on my brow
dandrews
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Re: Little Forty

Post by dandrews »

Oil filter strap wrench, preferably rubber rather than chain variety.
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