Magneto earth switch does not stop the spark
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Magneto earth switch does not stop the spark
I have yet to run the engine of my '54 VH500. The magneto produces a good spark when turning over the engine with the kickstart but I am concerned that I will not be able to stop the engine running because earthing the magneto via the earth wire does not stop the spark!
Am I missing something?
The earth wire shows continuity and is in contact with the engine during testing but still I get a spark at the spark plug.
Dennis
Am I missing something?
The earth wire shows continuity and is in contact with the engine during testing but still I get a spark at the spark plug.
Dennis
1955 VH500 alloy head
1956 NH350 restoration in progress
1956 NH350 restoration in progress
- simon.holyfield
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Re: Magneto earth switch does not stop the spark
Earth wire? Do you mean the magneto body earth? Ariel's don't normally have an earthing end cap...
cheers
Simes
'51 Square Four,
'58 Huntmaster,
'42 W/NG,
'30 Model A
https://ariel-square-four.blogspot.com
Simes
'51 Square Four,
'58 Huntmaster,
'42 W/NG,
'30 Model A
https://ariel-square-four.blogspot.com
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Re: Magneto earth switch does not stop the spark
I use the valve lifter to stop mine.
As simon says there isn't an earthing stop - usually - fitted to the
magdynos usually fitted to singles.
As simon says there isn't an earthing stop - usually - fitted to the
magdynos usually fitted to singles.
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Re: Magneto earth switch does not stop the spark
hi i have a new mag cap with a earth switch on my NH and a valve lifter i use the switch to stop the engine being started and to stop it wet sumping when it is left for a long time
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Re: Magneto earth switch does not stop the spark
Thanks both. I misunderstood what the earth terminal on the magneto is for. I know understand that is to earth the magneto body and not the points. I see that you can buy an end cap that includes a contact to earth the points to stop the spark and hence stop the engine. However, if the original method of stopping the engine is to use the exhaust valve lifter I will do that for now. I will also use the earth terminal to bond the magneto (and dynamo) to the engine and frame.
Dennis
Dennis
1955 VH500 alloy head
1956 NH350 restoration in progress
1956 NH350 restoration in progress
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Re: Magneto earth switch does not stop the spark
hi dennis i have fitted a earth on the mag to the engine and gearbox plate i found it made it start and runs better i did do , a post about it last year when i was rebuilding my NH
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Re: Magneto earth switch does not stop the spark
Johnny,
Thanks I plan to do that as well.
Dennis
Thanks I plan to do that as well.
Dennis
1955 VH500 alloy head
1956 NH350 restoration in progress
1956 NH350 restoration in progress
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Re: Magneto earth switch does not stop the spark
glad johhny mentioned the earth wire because i have also noted another indicator to a problem that might occur .
when i found that my NH magdyno magneto mounting bolts had become loose i had experienced erratic charging on the ammeter and a slight misfire but only found the mag loose when i happened to put my hand on it to check something else and found it wobbled a bit .
it may help anyone else with a similar charging issue occur to spot a loose magneto mounting .
i now check the magneto for movement regularly and will also put an earthing wire from the mag .
does the earthing wire go to the battery earth via wiring loom or anywhere particular on the frame , i have neg earth system myself .
cheers , ian
when i found that my NH magdyno magneto mounting bolts had become loose i had experienced erratic charging on the ammeter and a slight misfire but only found the mag loose when i happened to put my hand on it to check something else and found it wobbled a bit .
it may help anyone else with a similar charging issue occur to spot a loose magneto mounting .
i now check the magneto for movement regularly and will also put an earthing wire from the mag .
does the earthing wire go to the battery earth via wiring loom or anywhere particular on the frame , i have neg earth system myself .
cheers , ian
- simon.holyfield
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Re: Magneto earth switch does not stop the spark
My magneto earth is a short (3") wire that goes to the adjacent crankcase stud.
cheers
Simes
'51 Square Four,
'58 Huntmaster,
'42 W/NG,
'30 Model A
https://ariel-square-four.blogspot.com
Simes
'51 Square Four,
'58 Huntmaster,
'42 W/NG,
'30 Model A
https://ariel-square-four.blogspot.com
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- Holder of a Golden Anorak
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Re: Magneto earth switch does not stop the spark
hi i fitted my earth form the mag to the 1/4" bolt on the engine plate that supports the engine that the mag sits on , and i think it looks very neat with the wire running straight down , and not fitted to the engine
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