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scot taco

TY250 A points setting

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1 hour ago, scot taco said:

I bought the points at my local NAPA auto parts store. I just asked for some from an early 70,s Ford 302 or inline six cylinder and I believe the ones I put in were from a six cylinder in a Ranger truck. I mounted them under the tank on the HT coil bracket.

Ok. Thanks ScotTaco. I’d appreciate a picture of the hook up. 

Gracias. 

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Can't imagine you can swap the ignition source coil for the lighting coil and expect the motor to run properly.Most condensers are .22 mf  and can be mounted external from the points plate.Contact breakers are pretty specific and usually set at .012-.016 " or .3-.4 mm

 

 

 

 

 

 

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Sorry motosolex,I meant to say that I bought the condenser at the parts store and mounted it under the tank not the points.

And yes, swapping the the coils did work and she runs fine.I,m not sure if they are the same part number or not.

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1 hour ago, scot taco said:

Sorry motosolex,I meant to say that I bought the condenser at the parts store and mounted it under the tank not the points.

And yes, swapping the the coils did work and she runs fine.I,m not sure if they are the same part number or not.

I've also run a TY (and a Bultaco) using a lighting coil as the ignition stator coil and it went fine. Yes the voltage generated will be different because there are different number of coil windings, but it is obviously close enough to work well enough.

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On 8/6/2017 at 3:13 AM, feetupfun said:

Adjust the points so they start opening at the correct piston travel before top dead centre with the flywheel turning in the running direction. It is the opening of the points that causes the spark.

The gap you end up with (when they are fully open) is not critical but once the points are set to provide the correct timing, is usually between 0.3 mm and 0.4 mm.

The position of the piston/flywheel when the points reach fully open is irrelevant.

TY backing plates are not adjustable.

Dwell angle is important, the length of time measured in degrees that the contacts are closed, allows the coil to charge up. Too small a gap and the spark will be weak....thats why the manufacturer states a contact breaker gap. TY 250 A ignition timing 3.1 mm btdc with contact breaker gap of 0.012/0.016” (inch) or thou. Quite right about gap after opening as timing is adjusted by points gap, but by design the dwell angle should be within spec. The genuine article contacts last for ages without too much wear, unless you ignore lubticating the heel of the contacts. Cleaning the contact faces too much or crappy copies can throw the timing out somewhat. Always best to use a strobe timing light to check timing marks align on the flywheel and crankcase.🙂

Edited by section swept
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Hello - we design, build and repair motorcycle generators, if you didn't already know this.

You have stumbled on a happy accident. A points magneto primary winding is typically 200 turns, the accident is that so is a 6 volt AC lighting coil.

It gets a bit techy from here on in.

These windings have a magnetic polarity and generators are often arranged so the windings go north-south-north-south in a ring. The lighting coil is often wound opposite to the magneto if they sit opposite each other.

Why is this of concern? A negative spark ignites the fuel 10% more easily than a positive, so magneto windings are wound and timed to the engine to give a negative spark.

If the lighting coil wound opposite to the magneto primary coil, it'll be giving a positive spark. In the real world this makes very little difference, but the designer of the generator will have taken this into account.

The really important thing to bear in mind that a lighting coil capable of running more than around 30 watts is going to burn the points and condenser to hell as it will produce way too much power!

If the iron core in the lighting coil is the same thickness as the points magneto it'll be roughly the same power output. If the lighting coil iron core is thicker, it will make too much power. People think its the copper wire that determine the power out/put. While this has an effect, its the amount of iron core that determines how much power the copper wire will be able to produce.

Magnetos need a magneto type HT coil, which is nothing more than a step up transformer. Automotive coils tend to be 12 volts and their primary resistance is too high to give the best spark when used on a magneto ignition.

Edited by rex
typo/spelling correction
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