Lazy Idle / Neutral Switch - Replace? Rebuild? Re-Engineer?

[Hotmop]

I know this is a recycled topic. Apologies.

 

I'm knee-deep in a clutch replacement/spline lube and figured, as we all have, why not take a look at that pesky "lazy idle switch".

 

A few questions to cover some hopefully new ground:

• Has anyone attempted to source the actual microswitch inside the assembly? It seems like a $2 problem with only a $165 solution from BMW. 
• If I were to replace mine with a new one, I assume the problems are all about the shaft oil seal and one should really replace that too?
• I assume you'll all tell me a failed design will just fail again. Has anyone's NOT failed? Ever met a bike that didn't have a lazy switch?  
• Is there a pin-out or diagram for the gear selector? I had the crazy idea that one could determine neutral from the gear switch being last in 1st but not in 2nd. An Arduino board and some hacking and maybe there's another way?

 

Thanks for your attention on an old topic. I'm always impressed with the compendium of Oilhead knowledge here.

 

[dirtrider]

1 hour ago, Hotmop said:

I know this is a recycled topic. Apologies.

 

I'm knee-deep in a clutch replacement/spline lube and figured, as we all have, why not take a look at that pesky "lazy idle switch".

 

A few questions to cover some hopefully new ground:

• Has anyone attempted to source the actual microswitch inside the assembly? It seems like a $2 problem with only a $165 solution from BMW. 
• If I were to replace mine with a new one, I assume the problems are all about the shaft oil seal and one should really replace that too?
• I assume you'll all tell me a failed design will just fail again. Has anyone's NOT failed? Ever met a bike that didn't have a lazy switch?  
• Is there a pin-out or diagram for the gear selector? I had the crazy idea that one could determine neutral from the gear switch being last in 1st but not in 2nd. An Arduino board and some hacking and maybe there's another way?

 

Thanks for your attention on an old topic. I'm always impressed with the compendium of Oilhead knowledge here.

 

 

Afternoon  Hotmop

 

I do have a pin-out of the gear position switch (I will look for it later if I can still find it)-- If I remember correctly BMW didn't use the gear position switch in the OEM application as it isn't a simple yes/no switch but uses a combination of individual switch outputs in combination to allow the RID to show the correct  gear position.  I believe the same gear position switch signal wires are also used  in other combinations for other gear position outputs.

 

Seeing there are 3 switches for 5 gear positions you will probably end up with the  neutral light flashing as you shift through some gear positions.

 

You could probably source a new internal microswitch but thoroughly cleaning usually clears them up.

 

Moisture/dirt is one way the switch gets lazy as well as a gear oil leak at selector shaft  causing issues.

 

Back when I had 1100 bikes I was going to drill a couple of holes in the neutral switch outer housing, then add  rubber grommets, connector tits,  & external hoses (top one to flood the switch housing with WD-40 & the other, lower one, for a crud drain). I figured if/when the switch acted up  I would just uncap the hoses then flush the switch assembly with WD-40 remotely. I never did that as I actually had very little neutral switch problems once I replaced the selector shaft seal & lubed the switch with Tri-Flow.  

 

Check your PM'm on this site as I sent you a pin-out picture (It's BMW proprietary info so can't post it publicly on this site).

[Hotmop]

I was thinking of drilling holes as well just to facilitate getting contact cleaner in and dirt/oil flushed out. The external hoses are an interesting idea. 

 

Even if I get mine working again, I think new seals might be worth it to delay any repeat failures in the future.

[Jim Moore]

The simple fix is to jump your clutch switch at the handlebar. Then it will start if the bike is in neutral or not.

[Hotmop]

I did read that solution for those stuck (or not wanting to be stuck).

 

It's one of those only slightly annoying problems that doesn't always get much attention for permanent fixes. Timing hall switches? There's a ton of info and resource to fix better than new. Neutral switch? Seems many say "Meh, I can live with it."

 

Because of that, I wonder if it's 90% of bikes? Does anyone have an original working switch? 

[dirtrider]

4 hours ago, Hotmop said:

I was thinking of drilling holes as well just to facilitate getting contact cleaner in and dirt/oil flushed out. The external hoses are an interesting idea. 

 

Even if I get mine working again, I think new seals might be worth it to delay any repeat failures in the future.

 

Afternoon Hotmop

 

Just be very carful in how your remove the old selector shaft seal as it is REAL easy to get in too far & damage the rear selector shaft bearing ( then you are looking at a full transmission disassembly)

[Jim Moore]

You can also turn on the key and jump hole 2 to hole 6 under the starter relay. "Vrooom!"