Coil Advice: - SV650.org

MrMessy · 13-08-05, 04:57 PM

I have a 200 Honda that I have has a runabout. The overnight when I came out of work it would not start. Anyway when I got it home I was checking plugs, point etc and noted a arcing noise from the coil when the points where opened

I fitted a replacement coil, bike started and running great

This coil makes the same noise if you flick the points open

Do they have an air gap to boost the spark

13-08-05, 05:54 PM

The points gap IS the way that the spark is produced on older engines.

If you charge a coil with a DC current, and break the circuit, the inductance of the coil causes a high voltage which is what is used for the spark.
Until electonic ignition came along, all petrol engines worked like that.

MrMessy · 13-08-05, 06:06 PM

Hi Muddycoffee,
Thanks but I know that, the same way has in an A/C transformer the alternating current causes the flux to change. Coils would not normally make an arcing noise as it is to do with magnetic fluxes and has you say opening of the points causes the firing of the high tension side.

13-08-05, 07:15 PM

I'm sorry for stating the obvious.
I wouldn't have thought that you should get an arching noise from a coil. Is it a brand new one or one from a breakers?
Are you sure that there isn't a crack in the insulation?

13-08-05, 09:45 PM

I used to use coil, but recently changed my boiler to a combi and now run it on gas :P

13-08-05, 10:31 PM

Quote:

Originally Posted by wheelnut

I used to use coil, but recently changed my boiler to a combi and now run it on gas :P

arrr yer tekkin't pizz out'r us accent theeyen? Av not erd o' a coyil fiyered enjin foh fowatee yeearh

Richie · 13-08-05, 11:02 PM

Quote:

Originally Posted by MrMessy

Do they have an air gap to boost the spark

no, there usually filled with a cooling oil.
the noise is the voltage field collapsing when the contact's breaker open, or a very slight laps in the insoluation.

I used to have this problem alot on the old V8 landrovers, but since Her Maj's Army has move to deisel L/R's we don't get it anymore, just ERG/Turbo/FIP problems now...

hope this helps

Sid Squid · 14-08-05, 08:34 AM

Noisy coil = insulation breakdown.

Some will continue working for ever like this, but it's extremely likely that the spark voltage will be reduced, only you can tell if this is having an effect on performance/economy.

13-08-05, 04:57 PM	#1
MrMessy Member Join Date: Sep 2004 Posts: 557	Coil Advice: I have a 200 Honda that I have has a runabout. The overnight when I came out of work it would not start. Anyway when I got it home I was checking plugs, point etc and noted a arcing noise from the coil when the points where opened I fitted a replacement coil, bike started and running great This coil makes the same noise if you flick the points open Do they have an air gap to boost the spark

13-08-05, 06:06 PM	#3
MrMessy Member Join Date: Sep 2004 Posts: 557	Coils Hi Muddycoffee, Thanks but I know that, the same way has in an A/C transformer the alternating current causes the flux to change. Coils would not normally make an arcing noise as it is to do with magnetic fluxes and has you say opening of the points causes the firing of the high tension side.

14-08-05, 08:34 AM	#8
Sid Squid No, I don't lend tools. Mega Poster Join Date: Jul 2003 Location: Skunk Works, Nth London Posts: 8,680	Noisy coil = insulation breakdown. Some will continue working for ever like this, but it's extremely likely that the spark voltage will be reduced, only you can tell if this is having an effect on performance/economy. __________________ If an SV650 has a flat tyre in the forest and no-one is there to blow it up, how long will it be 'til someone posts that the reg/rec is duff and the world will end unless a CBR unit is fitted? A little bit of knowledge = a dangerous thing. "a deathless anthem of nuclear-strength romantic angst"

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13-08-05, 05:54 PM	#2
muddycoffee Guest Posts: n/a	The points gap IS the way that the spark is produced on older engines. If you charge a coil with a DC current, and break the circuit, the inductance of the coil causes a high voltage which is what is used for the spark. Until electonic ignition came along, all petrol engines worked like that.

13-08-05, 07:15 PM	#4
muddycoffee Guest Posts: n/a	I'm sorry for stating the obvious. I wouldn't have thought that you should get an arching noise from a coil. Is it a brand new one or one from a breakers? Are you sure that there isn't a crack in the insulation?

13-08-05, 09:45 PM	#5
wheelnut Guest Posts: n/a	I used to use coil, but recently changed my boiler to a combi and now run it on gas :P