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Neutral light issue

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Spanner McFettler:
I've seen a couple of other threads that mention this but none that particularly answer my problem. Following the rebuild of my CB750K7 the neutral light stays on regardless if the bike is in gear or not. The switch is good because I've tested it, continuity is good with no shorts anywhere so I'm stumped what may cause this? When I had the engine out of the frame I did a top end rebuild but left the bottom end alone, once the engine was back in the frame I popped my little finger in the neutral switch hole and whether in or out of gear I could feel the bit that engages the ball on top of the neutral switch and it didn't seem to move. Does this sound like a gear drum selector or bent selector fork issue? I suspect this will involve getting the engine out again and looking at the transmission. The engine runs perfectly but the gearbox is a little temperamental, hard to select neutral from 1st when stopped and occasionally a bit clunky when engaging a gear, now and then I've had a false neutral too. I've probably answered my own question but would appreciate any tips, cheers.

K2-K6:
First its worth checking continuity in situ if you've not done that to see if it changes.

Take wire off switch, then check continuity of switch only while flipping it in and out of neutral to see if the mechanical/ electronic transfer does anything at all.
If you get a result which confirms either way, then you can go from there as to what should be checked next.

K2-K6:
To add, during checking it's continuity to earth via the switch connection post that you should see change when going into neutral.

After that, you can check the wire to the switch by taking the nuetral bulb out of it's holder and then checking for continuity again from the wire end that attaches to the switch across to a competent earth point. This should have no connection to earth and give you no continuity when checking like that.

Bryanj:
As i remember it the part that makes the neutral switch work is a machined dimple in the selector drum allowing the ball on the end of the switch to move out father and create a ground to illuminate the lamp, it is 100% impossible for this dimple to fail so you problem is either a grounded wire or faulty switch

Trigger:
Try this that drove me mad once and worth a try.
On the ring crimp terminal with single wire to the switch, the ring maybe touching the outside of the natural switch causing it to earth. Slide a bit of paper under the ring clamp and see if the light goes out.
If the light does go out, then bend the end of the ring clamp away from the switch. I have found that some non original ring clamps that are a tad longer, so touched  ;)   

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