neutral switch


17 replies to this topic
  • gdbarr1976

Posted July 09, 2009 - 11:20 AM

#1

Just curious, what does the neutral switch do? Does it change the timing to make it easier to start in neutral? If it is disconnected will you be able to tell a difference in starting or while running? If it went bad, shorted whatever, would I be able to tell?

  • grayracer513

Posted July 09, 2009 - 11:35 AM

#2

Your second question is part of your answer. Other than that, it lowers the rev limit in neutral to about 7000.

It works by grounding the lead from the CDI. When the CDI see a ground on that circuit, it responds with an alternate timing map and a lowered rev limit. Thus, anything that causes there to be a ground on that circuit will cause the CDI to think the bike is in neutral all the time. An intermittent ground could have the effect of causing a misfire over 7000 rpm as the rev limit shifts between normal/lowered.

An open wire means no neutral signal, no lower rev limit, and possibly slighlty harder starting with an increased tendency to kick back.

Some 426's actually start better with the switch disconnected because the tuning is such that the engine likes more advance when starting.

  • gdbarr1976

Posted July 10, 2009 - 06:19 AM

#3

Your second question is part of your answer. Other than that, it lowers the rev limit in neutral to about 7000.

It works by grounding the lead from the CDI. When the CDI see a ground on that circuit, it responds with an alternate timing map and a lowered rev limit. Thus, anything that causes there to be a ground on that circuit will cause the CDI to think the bike is in neutral all the time. An intermittent ground could have the effect of causing a misfire over 7000 rpm as the rev limit shifts between normal/lowered.

An open wire means no neutral signal, no lower rev limit, and possibly slighlty harder starting with an increased tendency to kick back.

Some 426's actually start better with the switch disconnected because the tuning is such that the engine likes more advance when starting.


Interesting. Thanks Gray!

  • gumbellion

Posted September 30, 2009 - 05:15 PM

#4

So if I wanted to remove my neutral switch would I just not plug in the lead from it? Could I just cut the wires coming from the switch and forget about it? The reason I ask is because i changed my crank cases and it says there should be a pin inside the switch and mine seems to be missing. I took the switch out after the cases were separated due to a rounded screw. Thanks

  • Polar_Bus

Posted October 01, 2009 - 02:42 AM

#5

If memory serves me correctly, this was referred to as the "blue wire" mod way back in the early 2000's when the YZ/WR's first came out..

  • grayracer513

Posted October 01, 2009 - 08:48 AM

#6

If memory serves me correctly, this was referred to as the "blue wire" mod way back in the early 2000's when the YZ/WR's first came out..

It was.

So if I wanted to remove my neutral switch would I just not plug in the lead from it? Could I just cut the wires coming from the switch and forget about it? The reason I ask is because i changed my crank cases and it says there should be a pin inside the switch and mine seems to be missing. I took the switch out after the cases were separated due to a rounded screw. Thanks

If there's no contact pin in it, it already doesn't do anything, so nothing that is done with the wire (outside of grounding it at some point between the CDI and the switch) will have any effect on anything.

  • gumbellion

Posted October 01, 2009 - 10:51 AM

#7

I looked at the wiring harness last night and it looks like the PO already did the Blue wire mad. So im guessing that there was never a pin in there. So if i leave it hooked up for show as it is it wouldnt cause any issues. I just want to make sure because im installing a WR stator and want to make sure i dont have something stupid going on as my wiring is already starting to look a little funky

  • JJRace

Posted October 02, 2009 - 07:35 AM

#8

DRD makes a nuetral switch block off. That way you can remove the switch and all the wiring. Save a few grams.

  • grayracer513

Posted October 02, 2009 - 07:38 AM

#9

All of my 450's start so much better in neutral than in gear that I have an experiment in mind.

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  • Wiz636

Posted October 14, 2009 - 09:19 AM

#10

All of my 450's start so much better in neutral than in gear that I have an experiment in mind.


My bike is almost impossible to start in gear...it sure would be nice to fix that for hare scramble starts. Are you thinking the neutral switch might have something to do with that?

  • grayracer513

Posted October 14, 2009 - 09:37 AM

#11

My bike is almost impossible to start in gear...it sure would be nice to fix that for hare scramble starts. Are you thinking the neutral switch might have something to do with that?

Yes. I'm considering tying into the N switch lead and running it to a second button on the bars, probably throttle side, that I can use to ground the lead while the bike's in gear. I don't know how much of the difficulty with in-gear starts is clutch drag, and how much is timing, but this should tell me one way or other.

  • Wiz636

Posted October 14, 2009 - 09:44 AM

#12

Yes. I'm considering tying into the N switch lead and running it to a second button on the bars, probably throttle side, that I can use to ground the lead while the bike's in gear. I don't know how much of the difficulty with in-gear starts is clutch drag, and how much is timing, but this should tell me one way or other.


I am anxiously awaiting your findings.

  • cowboyona426

Posted October 14, 2009 - 09:46 AM

#13

I am anxiously awaiting your findings.

As am I.

  • grayracer513

Posted October 14, 2009 - 09:46 AM

#14

I am anxiously awaiting your findings.

It's going to be a while. I'm in the middle of 3 big projects right now.

  • Wiz636

Posted October 14, 2009 - 09:55 AM

#15

What is the downside if I were to simply disconnect the wiring? Rev limiter kicking in too early?

  • grayracer513

Posted October 14, 2009 - 10:46 AM

#16

If you disconnect, the switch will not be able to ground the lead, and the CDI will never enter the neutral mode. The timing will stay as it is in gear, and if the timing is part of the reason it's hard to start in gear, it will become cranky in neutral, as well.

Disconnecting won't affect in gear starts at all, because the lead is open when you're out of neutral.

  • rufusz

Posted October 16, 2009 - 03:33 AM

#17

Really nice would be if it would automatically ground (let's call it engage) when the engine stalls (= is not running). This can be done pretty easy, by using a transistor/tiristor that will disengage wire when it is powered.
Possible problem: When you start kicking it, the generator will already produce power before the piston will reach tdc and the engine could fire and if the transistor/tiristor reacts also at this low voltage, it will automatically disengage. So also a proper transistor/tiristor is needed that will not engage at low voltage and/or voltage comparator.

  • grayracer513

Posted October 16, 2009 - 06:17 AM

#18

An oil pressure switch would be much simpler, but so far, we're not sure that grounding the blue wire is even a solution.





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