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scot taco

TY250 A points setting

12 posts in this topic

What is the correct procedure for setting the points gap?

I had the primary stator coil give up the ghost this spring.I then put the lighting coil in its place along with a new set of points and condenser.Checked for spark,which was good and back in the corner she went until last weekend.

It was very reluctant to start and when it briefly did it sounded really out of time so I shut it down and took the Sherpa T.

Maybe there are other problems in my using the lighting coil,but I would like to make sure that I have the points set correctly before anything else.

I think the way that I did it was to turn the flywheel until the points looked to be fully open and then set the gap? I want to give it one more try before I order up a new electronic ignition.

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Bring piston to top dead center and set points to .015 - .016 of an inch

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The position of the backplate is important in setting the timing. Do you know the timing figure for the bike, ie the point at which the points should just start to open? From distant memory it was 1.8 mm before tdc for the TY175. You can check it using a depth gauge and multimeter. Failing that bolt the backplate in the central position on its slots and set the correct points gap when fully open. If the bike starts and runs at that you can try adjusting the backplate one way or the other to advance or retard the timing until it feels/sounds about right.

No need to go to the expense of an electronic system if it's just a case of setting the timing, though I'm dubious about using the lighting coil in place of the ignition coil.

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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.

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Thanks to everyone for the help.

I reset the points and still had issues and then put in a new spark plug and now she is running.I guess that I had forgotten the KISS rule.:wall:

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Scot I never heard about replacing the coil the way you did. Please give us feed back. I normally take the lighting coil out, if I can use them as replacement, I'll be more careful in storing them.

Guy

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I'd fit an electric ignition , fit once and forget

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I've been using TY250 twinshocks for the last 11 years, only fitted one set of new points in that time that I can remember.They are the one bike I've had that I wouldn't bother to fit electronic ignition on,the points setup is fine. Just fitted Electrex world to my son's road going D14/4 Bantam and it has completely transformed it,how it starts,runs and pulls. My C15  and my AJS both run modern systems for the obvious benefits, but the TY250, nah - wouldn't bother.

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Guy, I will let you know how/if it works when I get a chance to ride it maybe this weekend.

When it comes to electrics I really am a novice idiot so I wont be too surprised if something does not work right.

Here is a photo of what I did.The new condenser is mounted under the tank and I bought it at the automotive parts store.

 

 

post-17837-0-26992500-1482864515.jpg

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Don't forget to check the keyway, small things are important, trust me. 

Guy

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when refitting the flywheel, be prepared to push the points open with a screwdriver or similar so as to not damage the heel of the points. points get ruined by the f/w centre

being forced past the moving arm of the points.

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Just an update. I had a chance to ride it tonight around the backyard for 10-15 minutes.

It started first kick and will sit and idle nicely.

In first gear plunking along as slow as she will go it is not real smooth and kind of lunges with every power pulse.Maybe normal but it has been so long since I have ridden it that I don,t remember.

Whack the throttle in first gear and she comes up but sounds or feels a bit flat.Did the same in second gear and it was more responsive and almost put me on my back.

I have the points set at 15 thou and might try to play with that or find a better way to check the timing but all in all I,m just happy that it,s up and running again.Hopefully I can get out this weekend and put more time on it.

Thanks to all for the help

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