Almost there... no spark though

[Iamtimtipton]

Hey guys,

I almost have my 78 xs400 ready, I put it all back together today, new air and oil filters, and cleaned carbs. Now I am turning it over and wont fire.

I just check and though new plugs, no spark on either side. Where should I start?

Thanks,
Tim

 

[2cvtract]

Hi

I would follow the trail starting with the cobtact points. Clean them and set them. Then follow the wires to the coil (well harness in fact), are they connected?

Then you could check the coils and make sure you have 12v on the red/white wire going to the coil. And mesure the resistance of the coils. If you don't get 12v, it could be the cutoff on the handlebar or the contact switch which is faulty or disconnected in the front headlight?

If not then measure resistance of plug cap.

Well that's a start, if the run cutoff on the handlebar is in the correct position.

Good luck
Bob