Forty Plus SJP 29215 daft question

[Keith.P]

Just ask Stelios, he seems to know everything now.

[robhc1000]

I will check ohms, should there be a voltage anyway or would you need to spin flywheel? I have another 40+ powerhead from a seized engine, will check which one that is.

[robhc1000]

Right, removed flywheel nice and easy, set multimeter to 2k on resistance and nothing from ht lead to head, if I connect from points box to head it reads 0.02?????

[phil]

Remove the spark plug wire from the stator plate and measure between the metal point it touched on the coil and the stator plate which is ground. Should be around 3000-4000 ohms. Clean the points with some 320 grit auto body wet and dry sandpaper, then clean with alcohol or lacquer thinner or the like. Check gap is correct, replace flywheel, should have spark. Also check spark plug wire on on ohms x 1 scale or lowest scale you have if the meter is digital. Should be zero.

[robhc1000]

Remove the spark plug wire from the stator plate and measure between the metal point it touched on the coil and the stator plate which is ground. Should be around 3000-4000 ohms. Clean the points with some 320 grit auto body wet and dry sandpaper, then clean with alcohol or lacquer thinner or the like. Check gap is correct, replace flywheel, should have spark. Also check spark plug wire on on ohms x 1 scale or lowest scale you have if the meter is digital.

I tried to measure from coil to stator plate (bit thats underneath the flywheel and same size?) Nothing

[phil]

That won't do then. You said you had a stuck motor, you might want to check that coil, maybe it's good, if not, you need a coil it seems. Your meter is working on the ohms scale right? Good battery and all that?
Yes, stator plate is the Ali base piece same size as flywheel.

[robhc1000]

Multi meter is set on 2k setting with new battery, will check voltage of other one but looks even older and in worse condition. Hopefully sortable as rest of engine coming apart nicely and looking ok.

[Oyster 49]

The multimeter needs to be on the 20K ohm scale. as others have said you need to put one probe on the HT output on the coil (Where the HT lead sits) The other probe needs to go on the base plate. You are looking for resistnace of 3-4 Kohms.

If you don't get that then your coil is duff I'm afraid. Always best to fit a new one, as an old one will be full of green mush, and could fail at any time. Consider fitting a new HT lead too.

[robhc1000]

The multimeter needs to be on the 20K ohm scale. as others have said you need to put one probe on the HT output on the coil (Where the HT lead sits) The other probe needs to go on the base plate. You are looking for resistnace of 3-4 Kohms.

If you don't get that then your coil is duff I'm afraid. Always best to fit a new one, as an old one will be full of green mush, and could fail at any time. Consider fitting a new HT lead too.

Does not appear to be outputting anything on either coil so expect they have expired after only 63 years The HT lead looks fairly new, will look into costings for a replacement coil or a complete wipac mk2 and flywheel.
Many thanks.

[robhc1000]

I had a friend check coil for me and it has been confirmed as expired. Contacted John and he put me onto Villiers who do a exchange service for £75, you send old unit and it comes back refurbished and good to go.

[sassi232]

Re. Replacing 60 year old villiers coil,whilst I can't argue the safety aspect,over the years I have used,abused and bodged 20 plus Seagulls of all types including a WW2 one and have never heard of or experienced a coil failure. Poor spark is usually due to poor connections or the magnets needing re-magnetising.