Author Topic: CR250M ignition problems  (Read 1696 times)

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Offline c_stewart

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CR250M ignition problems
« on: July 25, 2015, 01:01:48 pm »
I have finished building the bike with new points, new coil, new plug but can't manage to get any spark! I've checked the wiring diagram and although I have wired my bike correctly, I don't fully understand how the electrical system is supposed to work. Does anyone have any tips for figuring out where the problem is?

Offline Rossvickicampbell

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Re: CR250M ignition problems
« Reply #1 on: July 25, 2015, 01:57:17 pm »
have you made sure you have taken any paint etc off where it needs to earth?  I had the same issue with a powdercoated frame - once I ground it off to bare metal miraculously had spark again  ;D
1974 Yamaha YZ360B
1980 Honda CR250R - Moto X Fox Replica

Offline bazza

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Re: CR250M ignition problems
« Reply #2 on: July 25, 2015, 02:25:38 pm »
Earth?  :D :D
Once you go black  you will never go back - allblacks
Maico - B44 -1976 CR250- 66 Mustang YZF450,RM250
Embrace patina

Offline Rossvickicampbell

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Re: CR250M ignition problems
« Reply #3 on: July 25, 2015, 03:27:33 pm »
oops - yeah - right idea wrong..............................
1974 Yamaha YZ360B
1980 Honda CR250R - Moto X Fox Replica

Offline smed

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Re: CR250M ignition problems
« Reply #4 on: July 25, 2015, 05:05:32 pm »
They are a pretty basic system, Did the bike have spark before you done the rebuild? They also have a condenser,That maybe crook,or the windings?

Is the point gap correct? When you installed the new points did you replace the wire in the correct order on the bolt the same as before? If not it could be earthing out :) 

Offline c_stewart

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Re: CR250M ignition problems
« Reply #5 on: July 25, 2015, 06:39:55 pm »
It turns out my new replacement coil is a dud, after much head scratching I decided to plug in the old coil and hey presto, I've got spark!! The only problem is once I finally started the bike for the very first time it only ran for 2 seconds and now the engine is seized  :-[ time to pull it all back down again... I'm starting to think this bike is cursed!