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400ex rebuild
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Posted by: honda_rider456

I just rebuilt my 400ex and it won't start. i adjusted the valves and cleaned the carb out what am i forgeting? also it is making a noise in the topend it was making it before i adjusted the valves and never changed once adjusted.

Posted by: zrpilot

First, does it have spark? Is the plug OK? Is the plug wet? Is it making compression?

Posted by: honda_rider456

I put a new plug in it and i tested for spark before i adjusted the valves. I just checked it again and no spark. The plug is wet and I have compression. What would be the cause of no spark?Electrical is my weakness so any help would be greatly appreciated.

Posted by: zrpilot

First you have check the controls, specifically the left handle bar control pod has a reputation for failing and causing electrical problems. Is the kill switch grounding out?

Oh, do you have an aftermarket CDI in it? Some of the re-badged XR250 CDI boxes will cause a no-spark condition if the cranking speed is to slow. If you don't know, you might want to get a used CDI off of the For sale section here (or Ebay) to try..

Good luck