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Discussion Starter · #1 ·
Hi all,

Need some help with my 1970 CB250. I have brand new coils that i have installed (coils are from Common Motor). I have been trying to start the bike when this is occuring (I have not been able to get it to start). I should mention that the engine has not started in 20 years and has been recently fully rebuilt.

Right coil - no spark and when i put my hand on the coil its dam hot. I have double checked the plug - it works. No such issues with the left coil. I have been back through the wiring and im pretty confident that its all ok.

Any thoughts or fixes would be appreciated. Im at a loss on this one.

Cheers Owen
 

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Are your points opening? If they are not opening, it will not break the circuit, and the coil will just keep charging.
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Are your points opening? If they are not opening, it will not break the circuit, and the coil will just keep charging.
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+1

That's my guess as well.

Since you've also recently rebuilt it, is it safe to assume that new points have been installed? If that's the case, it's not uncommon to get the order of the insulating washers wrong and to find out that the points arm or arms are not insulated from the backing plate. In this scenario, even though the points open, current it still flowing.
 

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Yes, make sure all those tiny insulating washers are in the right places and that the points are actually opening and closing. Also make sure the wires connected to the points aren't touching the points housing or chrome cover when it's installed - it's really tight in there. Don't leave the ignition turned on for very long if the bike isn't running - the coils will overheat and burn up.
 

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Discussion Starter · #5 ·
Thanks for the tips lads. I was pretty confident that i had set those points but based on your advice I went down this morning and had another look. Set perfectly. Check the spark again and there was spark! I gave the wiring from the points to the coil a wiggle and it stops sparking again. Found the issue! Dodgy connection there somewhere.

I rewired it gave it a go.....first start in 20 years. I have spent 9 months work rebuilding this. To say im pleased would be an understatement! :cool:

 
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