Yamaha Chappy 1978 LB50 No Spark

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42653steve

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I have a 78 Yamaha Chappy has no spark but with a test light I have power up to the wire that plugs into coil wire. Best way to test coil still on bike. Need help. Thanks
 
I have a 78 Yamaha Chappy has no spark but with a test light I have power up to the wire that plugs into coil wire. Best way to test coil still on bike. Need help. Thanks

take the plug out, connect it to plug boot/lead and hold threaded part against the head and kick it over a few times see if there is spark.
should be able to use the kicker with your hand as there wont be any compression with plug out.
If no spark then chance are you have a faulty coil or could be the connection of your ignition lead/boot.

good luck
 
Could be your spark plug too, try another plug, if you don't have a spare just borrow one from ya lawnmower to check.
 
Sounds like the points are always closed(not opening). The coil needs the points to break the flow of voltage to the coil, it will only spark when the circuit is broken (points open). Does the test light flicker when you kick it over or is it on solid? Check your points gap
 
Last edited:
Points gap is 0.35mm or 0.014 inches (14thousandths of an inch). You will need feeler gauges to adjust the points to this measurement. Take off the cover on the stator, line up the "F" mark on the stator to the mark on the cases (at the 12oclock position). When lined up on the f mark, you will be able to see the points through the cut out on the stator.
Loosen the set screw (phillips head) on the points and the points will be loose allowing you to open and close the gap, put the feeler guage between the points and tighten the set screw. Once the points are set you want to feel a slight drag on the feeler gauge when it goes through the points. Jump on youtube and google how to set points on a small motorcycle, it will teach you more seeing it than anyone will be able to describing it, perhaps look up how to do it on a GT80, much more popular than a chappy but exactly the same procedure
 
Points gap is 0.35mm or 0.014 inches (14thousandths of an inch). You will need feeler gauges to adjust the points to this measurement. Take off the cover on the stator, line up the "F" mark on the stator to the mark on the cases (at the 12oclock position). When lined up on the f mark, you will be able to see the points through the cut out on the stator.
Loosen the set screw (phillips head) on the points and the points will be loose allowing you to open and close the gap, put the feeler guage between the points and tighten the set screw. Once the points are set you want to feel a slight drag on the feeler gauge when it goes through the points. Jump on youtube and google how to set points on a small motorcycle, it will teach you more seeing it than anyone will be able to describing it, perhaps look up how to do it on a GT80, much more popular than a chappy but exactly the same procedure
I just started working on this again. I forgot to mention on the wiring harness on the right side of air box are two wires a green with yellow stripe and a brown that are not plugged in to anything. where do these plug in at. Thanks
 

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