Neutral switch??


16 replies to this topic
  • harwood39

Posted March 04, 2008 - 10:28 PM

#1

well i was looking over my bike as i am getting ready to throw some pj1 paint on it, and i noticed this sensor on the side of the case. I did some more research, and found out its a neutral switch. Why did yamaha put this on there if its a dirtbike? Also, the previous owner cut all the wires off it. Why?

This may be a very stupid question, but im just wondering...

  • grayracer513

Posted March 04, 2008 - 11:07 PM

#2

The neutral switch does two things, both by grounding the neutral sensing lead from the CDI. The presence of a ground at this lead alerts the CDI that the bike is in neutral. In response, the CDI lowers the rev limit to around 7000 rpm, and then retards the base timing a few degrees to help the bike idle smoothly at a little lower speed, and to make it less likely to kick back during starting. It has absolutely no effect on performance in gear as long as there is no ground at the one wire that is actually connected to it.

People cut the wires for various reasons. sometimes they damage the switch by not assembling it correctly, or by failing to remove it before reinstalling the shift cam. Rarely, the switch may short, causing the CDI to assume a neutral state when the bike is really in gear.

There is also the erroneous belief that disconnecting the switch will increase ignition strength and make the bike start better, but this is not true.

From your point of view, if you are happy with the way the bike runs, you don't really need to do anything with the switch at this point.

  • harwood39

Posted March 04, 2008 - 11:18 PM

#3

Well i do have a hyabusa coil on it if that has anything to do with it. Honestly, i love the way it runs. starts first kick, and idles great.

  • King_Air

Posted March 05, 2008 - 04:08 AM

#4

Well i do have a hyabusa coil on it if that has anything to do with it. Honestly, i love the way it runs. starts first kick, and idles great.


Then it seems that all is well. Just :thumbsup:

  • srfdwg2

Posted March 05, 2008 - 03:50 PM

#5

Explain the Hyabusa coil if you could please?Im sorry I did not want to high jack your thread/.

  • harwood39

Posted March 06, 2008 - 12:28 AM

#6

people install the coil off of a hyabusa for easier starting and less plug fouling.... idk exactly how its done wiring wise... but i know it works...

  • srfdwg2

Posted March 06, 2008 - 11:24 AM

#7

Harwood,you did a mod on your bike not knowing how it works?Bro if that plug is running super hot buh bye to the piston.

  • King_Air

Posted March 06, 2008 - 12:16 PM

#8

Harwood,you did a mod on your bike not knowing how it works?Bro if that plug is running super hot buh bye to the piston.


I think that the hyabusa mod may have been onHarwood's bike when he got it. In any case the hyabusa is a fairly common mod with no little negative feedback. If you are looking for information on this mod do a search. I am sure you could find a lot of information on it in here.

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  • William1

Posted March 06, 2008 - 12:53 PM

#9

I imagine the 'busa coil may have a few more coils in the secondary, creating a higher voltage spark. Only worthwhile if you are running very high compression, have leaky rings or valve seals. Otherwise, the performance gain is psychological.

And not, it cannot make the plug hotter.....

  • grayracer513

Posted March 06, 2008 - 01:26 PM

#10

Harwood,you did a mod on your bike not knowing how it works?Bro if that plug is running super hot buh bye to the piston.

It sounds like he's not the only one that doesn't know how it works.

The Hyabusa coil conversion is a way to get the coil-over-plug setup featured in all of the YZ450's onto a 426. The YZ450 coil would work, but as I recall, the issue was that the connector for it was not available outside of either buying the whole harness or clipping it off an wrecking yard bike. Suzuki sells the coil connectors as a harness repair part, so that made it simpler to use their coil.

The advantage to this setup is that, as William began, the coil output is better. The main benefit of that is that the resulting higher spark energy makes the bike start better and foul plugs less, especially when cold. Both of these were a problem with the 426 and 400 with the original coil. Higher spark energy also makes the bike less likely to misfire under marginal conditions such when running lean, or at high revs at light throttle.

No matter how much power is put into the spark itself, it will have no effect at all on the heat of the plug. That is controlled by the amount of porcelin exposed between the center electrode and the plug shell. The plug must stay hot enough to be able to burn away fouling deposits, but not so hot as to become a source of ignition just as a hot spot. Spark energy could be 10 times what it is without changing the heat of the plug.

  • EGPeil

Posted March 06, 2008 - 03:05 PM

#11

So the Hyabusa coil conversion wouldn't be worth while on the 03+ 450s?

  • King_Air

Posted March 06, 2008 - 04:09 PM

#12

So the Hyabusa coil conversion wouldn't be worth while on the 03+ 450s?


Not really

  • grayracer513

Posted March 06, 2008 - 04:25 PM

#13

Not at all.

  • William1

Posted March 06, 2008 - 06:40 PM

#14

It is really a 'bling' mod. The only advantage a COP (coil over plug) is you have to high tension lead (plug wire) to worry about getting broken or damaged.

  • grayracer513

Posted March 06, 2008 - 08:14 PM

#15

It is really a 'bling' mod. The only advantage a COP (coil over plug) is you have (no) high tension lead (plug wire) to worry about getting broken or damaged.

Sorry, not true:

The advantage to this setup is that ... the coil output is better. The main benefit of that is that the resulting higher spark energy makes the bike start better and foul plugs less, especially when cold. Both of these were a problem with the 426 and 400 with the original coil. Higher spark energy also makes the bike less likely to misfire under marginal conditions such when running lean, or at high revs at light throttle.


There is an element of bling in it, I suppose, given the location of the stock 426 coil. But the reason I said there is no benefit to the mod on a 450 is simply because they already have one.

  • harwood39

Posted March 06, 2008 - 10:21 PM

#16

no, i didnt know everything about the hyabusa coil, i knew it cleared the coil out of the way and made getting to the carb a lot easier. And i also knew it is very common and didnt do any damage. Yes, it was already done when i picked up the bike.

  • jeep40

Posted March 15, 2008 - 07:30 PM

#17

anyone knows how to remove the neutral switch?... i was traying to do so with a screw driver and it broke...





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