Doug044
ArboristSite Lurker
Rebuilding this saw and know nothing about this!! Please educate me!!
Can some one explain magneto breaker point
- Thread starter Doug044
- Start date
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thats the gap you need to set when fully open
so that it sparks at the instant that they open
so that it sparks at the instant that they open
the coil charges with the points together, when they open it fires the coil sending spark through the plug
Points gap, timing, air gap and edge gap
points gap: set saw to TDC and set the gap to spec, .35-.40mm is what seems to be fairly common.
set the timing, generally around 26 - 28 degrees before top dead centre. Most often there is a notch on the housing and on the flywheel. Just align those two making sure that when they align the gap starts to open.
Set the air gap- generally .2mm is the gap between the coil and magnets.
Edge gap - the position of the magnets the instant the points open. With the first two set correctly this should be too, this is the distance between the trailing edge of the N magnet and the leading edge of the armature plate of the coil. If it’s not right you must adjust the points gap to compensate. If you have to adjust the points gap, then go over it again to check you’re within spec on timing etc. there is a small amount of room for error, a degree probably isn’t worth pulling your hair out over.
you also have a capacitor and coil readings you need to check.
cap is generally acceptable if it’s within +/- 20% of its spec capacitance. Most saw caps are around 200nf, also you need to check it takes a charge, holds and charge and fully discharges.
Coil reading:
primary is generally around 1.5 ohms
Secondary is generally around 7.5kohms
I have all these topics covered in my YouTube channel which goes into detail if you want to skim through it. Same name as here.
points gap: set saw to TDC and set the gap to spec, .35-.40mm is what seems to be fairly common.
set the timing, generally around 26 - 28 degrees before top dead centre. Most often there is a notch on the housing and on the flywheel. Just align those two making sure that when they align the gap starts to open.
Set the air gap- generally .2mm is the gap between the coil and magnets.
Edge gap - the position of the magnets the instant the points open. With the first two set correctly this should be too, this is the distance between the trailing edge of the N magnet and the leading edge of the armature plate of the coil. If it’s not right you must adjust the points gap to compensate. If you have to adjust the points gap, then go over it again to check you’re within spec on timing etc. there is a small amount of room for error, a degree probably isn’t worth pulling your hair out over.
you also have a capacitor and coil readings you need to check.
cap is generally acceptable if it’s within +/- 20% of its spec capacitance. Most saw caps are around 200nf, also you need to check it takes a charge, holds and charge and fully discharges.
Coil reading:
primary is generally around 1.5 ohms
Secondary is generally around 7.5kohms
I have all these topics covered in my YouTube channel which goes into detail if you want to skim through it. Same name as here.
This may help explain things.
Mark
Mark
How on Earth did you decide to tear a machine apart? With no research?
breaker points...and since you have no idea, start over with a newer machine...
