|
Posted by z on July 6, 2009, 12:25 am
If you were Registered and logged in, you could reply and use other advanced thread options
> I have recently unearthed my old Suffolk Super Colt petrol mower after
> it laying dormant for 20 years. =A0I have cleaned the carburettor,
> checked the compression is O.K., cleaned and reset the points and plug
> but there is no visible spark at the plug gap. =A0I have substituted the
> spark plug with a new one but still no spark, even with the suppressor
> resistor shorted out. =A0
>
> However a neon timing lamp connected in series with the spark plug
> flashes weakly which suggests to me that the magneto may not be working
> properly. =A0The resistance measured between the HT plug lead and chassis
> is around 4500 ohms.
>
> I do not know much about magneto ignition but can anyone tell me if
> there should be DC continuity between the HT lead and ground and does
> this depend on whether the points are open or closed?
>
> Regards - Alan S
>
> --
> weathereye
off the top of my head, i would think that there should be continuity
between the HT lead and ground, and that it shouldn't depend on the
points, if you have any, which if it's a magneto you probably don't.
if there is no continuity, then it would seen the magneto has
opencircuited.
if there is continuity, then my guess is that the insulation has
weakened and the spark voltage is being limited at some value where it
can penetrate the insulation. i find that car ignition ht wiring often
degrades before 20 years.
| 
Yahoo! 
Google 
Windows Live 
del.icio.us 
digg 
Netscape 
XML site map