Author Topic: Just picked up a K75 - need input on the plan of attack  (Read 42236 times)

Offline oneplustwo

  • ^ Motobrick Curious
  • Posts: 109
Re: Just picked up a K75 - need input on the plan of attack
« Reply #50 on: June 26, 2018, 02:23:30 PM »
You got me curious so I've been reading too.  I haven't gotten into the weeds yet on the OEM control yet but I'm assuming you mean I can connect the yellow/brown wire from the ICU to auxiliary 1 input to determine whether or not to supply power to the FI relay?  Is there a downside to simply providing power to it with ignition on as default?  I don't know what the OEM control is beyond that obviously!

You're right on the motosign documentation.  I assume it's obvious once I receive it as it supposedly it comes with a connection diagram.  In the meantime, I found this:



Looks like they put together an option using diodes to have one light for both turn signals and then using two lights for oil and in this case, low fuel.  I would use oil and temp to your point as this isn't going to be any sort of touring bike!
  • San Francisco
  • 1990 K75S (in 1000 pieces)

Offline DEcosse

  • Motobrick Curious
  • Posts: 28
Re: Just picked up a K75 - need input on the plan of attack
« Reply #51 on: June 26, 2018, 02:53:06 PM »
I would personally prefer a starter interlock for safety - you can wire the start switch in series with parallel combination of Neutral/Clutch
  • CA, USA
  • Triumph Daytona 955

Offline DEcosse

  • Motobrick Curious
  • Posts: 28
Re: Just picked up a K75 - need input on the plan of attack
« Reply #52 on: June 26, 2018, 02:59:55 PM »
Only problem with the warning lights under that scheme is that means one of them is going to have to be green.
If you have the EFI relay powered on with ignition, pump is going to run continuously. I couldn't see way to control the output with the original older version but now you have more switchable outputs with the Aux function, so can readily use the Relay Control (already a (-) signal ) as an output control to mimic the EFI Relay. 
  • CA, USA
  • Triumph Daytona 955

Offline Laitch

  • Faster than a speeding pullet
  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 10120
Re: Just picked up a K75 - need input on the plan of attack
« Reply #53 on: June 26, 2018, 03:02:13 PM »
As I read some more on the newer one, you should be able to use Aux or 2 and control the output using the Yellow/Brown - that should work well with the same control as the OEM
If you can use either polarity on the Motosign, then couple of diodes are all you need and connect them directly - but again, you can use one of the aux as a driver if you need it be positive.
There's no documentation for the Motosign (that I could see) but imagine you will have separate +/- for each LED?
This isn't much but it's something.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline DEcosse

  • Motobrick Curious
  • Posts: 28
Re: Just picked up a K75 - need input on the plan of attack
« Reply #54 on: June 26, 2018, 03:03:17 PM »
Sorry can't edit - haven't read the fine print yet, probably not enough posts before I'm allowed that privilege :)

... you mean I can connect the yellow/brown wire from the ICU to auxiliary 1 input to determine whether or not to supply power to the FI relay? 

Noy, you won't be using the relay - the aux output will be taking the place of the relay and you will just control the aux output using that signal as the steering switch; so it will exactly mimic the OEM behaviour of the relay

  • CA, USA
  • Triumph Daytona 955

Offline DEcosse

  • Motobrick Curious
  • Posts: 28
Re: Just picked up a K75 - need input on the plan of attack
« Reply #55 on: June 26, 2018, 03:07:05 PM »
This isn't much but it's something.
Actually that is perfect!
It shows it is fixed (+) for the turns, but headlight, neutral and oil all have both wires so can be either polarity.
If you use diodes to free up one of turns, that will have to be a (+) input
  • CA, USA
  • Triumph Daytona 955

Offline Laitch

  • Faster than a speeding pullet
  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 10120
Re: Just picked up a K75 - need input on the plan of attack
« Reply #56 on: June 26, 2018, 03:13:09 PM »
Actually that is perfect!
It shows it is fixed (+) for the turns, but headlight, neutral and oil all have both wires so can be either polarity.
If you use diodes to free up one of turns, that will have to be a (+) input
Motogadget's site has all this information under a Downloads tab on the page of the instrument model that has been selected.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline DEcosse

  • Motobrick Curious
  • Posts: 28
Re: Just picked up a K75 - need input on the plan of attack
« Reply #57 on: June 26, 2018, 03:19:45 PM »
Motogadget's site has all this information under a Downloads tab on the page of the instrument model that has been selected.

You read my mind with the question "where is it" - so it's not actually under a 'downloads' page for the motosign per se, it's actually under the motoscope mini. That wasn't immediately obvious to me (ther site navigation is a bit strange sometimes)
Appreciated!  :2thumbup:
  • CA, USA
  • Triumph Daytona 955

Offline Laitch

  • Faster than a speeding pullet
  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 10120
Re: Just picked up a K75 - need input on the plan of attack
« Reply #58 on: June 26, 2018, 03:28:41 PM »
You read my mind with the question "where is it" - so it's not actually under a 'downloads' page for the motosign per se, it's actually under the motoscope mini.
That's because the motosign is a design function of the mini—Teutonic organization in action.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline oneplustwo

  • ^ Motobrick Curious
  • Posts: 109
Re: Just picked up a K75 - need input on the plan of attack
« Reply #59 on: June 26, 2018, 03:41:30 PM »

Noy, you won't be using the relay - the aux output will be taking the place of the relay and you will just control the aux output using that signal as the steering switch; so it will exactly mimic the OEM behaviour of the relay

Yes, that's what I meant (accidentally added relay) and so might as well use it!

I'm a little confused on your point for the turn signal input.  Wouldn't the input be a (+) coming from the m.unit paralleled from either of the turn signal outputs?  Or am I missing a fundamental issue here?

  • San Francisco
  • 1990 K75S (in 1000 pieces)

Offline oneplustwo

  • ^ Motobrick Curious
  • Posts: 109
Re: Just picked up a K75 - need input on the plan of attack
« Reply #60 on: June 26, 2018, 03:44:35 PM »
Oh, to follow up on your point for the neutral indicator.  Will that require one of RBM's boards or is there a simpler way?  I haven't deciphered the gear position indicator and neutral indicator parts of the schematic but my guess is that those reside in the lunch box and since I'm getting rid of that, I need to pull the wire from the transmission which needs a "translator" for whether or not it's in neutral?
  • San Francisco
  • 1990 K75S (in 1000 pieces)

Offline DEcosse

  • Motobrick Curious
  • Posts: 28
Re: Just picked up a K75 - need input on the plan of attack
« Reply #61 on: June 26, 2018, 05:10:49 PM »
... I'm a little confused on your point for the turn signal input.  Wouldn't the input be a (+) coming from the m.unit paralleled from either of the turn signal outputs? 

There are two inputs (lights) supplied for individual left & right lamps, with a common negative
Yes, you can use diodes from the two outputs to steer to just one of those lamps leaving one available for other options
But the one that is unused will require a (+) input - that logic is fixed as far as the tun lamps go.
It will also be 'green' which is not ideal as a 'warning' lamp but that is relatively minor nit.
The high beam can be either polarity but of course would be (+)
The Neutral and 'Other' can also be either polarity and you would likely want both of these as (-)

Quote
Oh, to follow up on your point for the neutral indicator.  Will that require one of RBM's boards or is there a simpler way?

There are three signals from the GPS - those are all three (-) -  i.e. connected to ground - when in neutral;
for other gears at least one of them is 'open' (pulled high as required externally)
You will find a few options in the forums - the most common is the use of multiple relays which is a bit 'clunky'

@RBM's board obviously does a lot more than just that function - you might ask him if he would be able to send you a stripped-down version with just the neutral decode chip.
Or with his kind permission DIY & use the part of the circuit that does that function on a mini-board





  • CA, USA
  • Triumph Daytona 955

Offline oneplustwo

  • ^ Motobrick Curious
  • Posts: 109
Re: Just picked up a K75 - need input on the plan of attack
« Reply #62 on: June 26, 2018, 06:19:41 PM »
The four relay option is kinda clunky.  But with micro relays, perhaps not too bad a solution.  I'll check with RBM though for any other ideas he may have.  In case others need a reference from this thread:

http://www.k100-forum.com/t2611p50-my-k100-cafe-racer-project-story#36465

Also, perhaps I don't need a neutral indicator.  This way, I can keep my left and right turn signals and turn the neutral indicator into the temp alarm.  My understanding is that I would just have to start the bike with the clutch in, which is typical practice for me anyway.  It would be nice to have the indicator while waiting at stop lights.  But it's not that hard to check to see if you're in neutral or not, right?!
  • San Francisco
  • 1990 K75S (in 1000 pieces)

Offline DEcosse

  • Motobrick Curious
  • Posts: 28
Re: Just picked up a K75 - need input on the plan of attack
« Reply #63 on: June 26, 2018, 06:37:42 PM »
http://www.k100-forum.com/t8674-aftermarket-gear-indicator-neutral-indicator-board-3-circuit-fuse-block

He has link in that to the User Manual which also includes the circuit for the neutral detect via a simple but effective NOR gate.
Note that you WILL need the drive transistor, even for an LED

You will see that he also offers a small compact pcb for the relay kit with the option to DIY assemble or just get it turn-key

Quote
My understanding is that I would just have to start the bike with the clutch in, which is typical practice for me anyway.

Well that would be with OEM start circuit - since you're using the M-Unit you can do what you like, including no interlock at all!
But as I suggested above, the simple wiring for the control signal for starter would be Neutral and Clutch switches in parallel, (so effectively an 'OR' situation) in series with the start switch
Or in your case, (eliminating neutral option) just the clutch switch (to ground) in series with the start switch. 
As you say this is not a huge ordeal to always use the clutch - my Triumph (actually ALL Triumphs) operate same way.

But would have to say I would want a Neutral indicator personally
  • CA, USA
  • Triumph Daytona 955

Offline oneplustwo

  • ^ Motobrick Curious
  • Posts: 109
Re: Just picked up a K75 - need input on the plan of attack
« Reply #64 on: June 27, 2018, 04:57:04 PM »
I think I may just wire the clutch switch in series with the momentary button for the starter.  That will be super clean from a wiring perspective and is interlock enough from a safety perspective for me.  Still waiting to hear back from RBM on the neutral PCB but I'm ok using that extra light for temp since finding neutral isn't all that difficult.

Anyone have opinions about using expandable wire cable sleeving and/or silicone tape to keep the wiring harness clean and tidy?  There's also slit braided sleeving and fleece cloth electrical tape that I've seen used.  Not sure if it really makes any difference but thought I'd ask what folks would recommend.

 
  • San Francisco
  • 1990 K75S (in 1000 pieces)

Offline DEcosse

  • Motobrick Curious
  • Posts: 28
  • CA, USA
  • Triumph Daytona 955

Offline oneplustwo

  • ^ Motobrick Curious
  • Posts: 109
Re: Just picked up a K75 - need input on the plan of attack
« Reply #66 on: June 29, 2018, 03:03:26 AM »
Any recos for clutch and throttle cables?  I need to figure out if the stock style will fit my new levers.  And also figure out how long they need to be.  Or I may get one of those DIY kits to cut to length and solder on the correct ends.
  • San Francisco
  • 1990 K75S (in 1000 pieces)

Offline rbm

  • ^ Quintessential Motobricker
  • Posts: 2281
Re: Just picked up a K75 - need input on the plan of attack
« Reply #67 on: June 29, 2018, 06:25:32 AM »
Bowden cable lengths are published on the drawings on RealOEM.
Clutch for high bars = 1625mm
Clutch for low bars = 1510mm
Throttle for high bars = 1142mm
Throttle for low bars = 1025mm
  • Regards, Robert
Toronto, Ontario

1987 K75 - Build Blog @http://k75retro.blogspot.ca/

Offline oneplustwo

  • ^ Motobrick Curious
  • Posts: 109
Re: Just picked up a K75 - need input on the plan of attack
« Reply #68 on: June 29, 2018, 11:26:45 AM »
Yes, I've seen the stock lengths. I'm using eBay clip ons that will be mounted to the top of the fork tubes that will stick out above the triple clamp by about 1.5".  I'm not sure how precise the lengths need to be, probably plus or minus 20mm or so would be good enough.  So I guess I'll need to mock it up and see in real life.  Probably more likely I'll need to make them myself.
  • San Francisco
  • 1990 K75S (in 1000 pieces)

Offline oneplustwo

  • ^ Motobrick Curious
  • Posts: 109
Re: Just picked up a K75 - need input on the plan of attack
« Reply #69 on: July 02, 2018, 11:43:23 PM »
Hi all,

It appears my new clutch needs a smaller ferule at the lever than the stock cable has.  I'm thinking I can just buy a stock cable and cut off the end and solder on my own ferrule on the end.  I haven't checked the throttle side, but perhaps the same situation.

Alternative ideas?

  • San Francisco
  • 1990 K75S (in 1000 pieces)

Offline johnny

  • TrailBrakingThrottleWhacker
  • ^ Quintessential Motobricker
  • Posts: 7650
  • Whacking...n...Chopping Sliding...n...High Siding
Re: Just picked up a K75 - need input on the plan of attack
« Reply #70 on: July 03, 2018, 12:17:40 AM »
greetings...

at your local gokart shop...

use the red locktite...


* s-l400.jpg (11.07 kB . 400x267 - viewed 441 times)

j o
  • :johnny i parks my 96 eleven hundert rs motobrick in dodge county cheezconsin  :johnny

Offline oneplustwo

  • ^ Motobrick Curious
  • Posts: 109
Re: Just picked up a K75 - need input on the plan of attack
« Reply #71 on: July 03, 2018, 01:29:46 AM »
Red loctite?  No need to solder?
  • San Francisco
  • 1990 K75S (in 1000 pieces)

Offline oneplustwo

  • ^ Motobrick Curious
  • Posts: 109
Re: Just picked up a K75 - need input on the plan of attack
« Reply #72 on: July 04, 2018, 11:46:27 PM »
Hey folks - got the front fender painted today. Not sure I’m going to keep it but figured I’d try it and take it off later if I didn’t like it.

Also, I took all the stuff out of the tank in prep for sealing. I think it’s worth replacing the pump and filter along with the associated hoses.

Three questions.

1. Is there another aftermarket pump like the Purolator that folks used to use before it went obsolete?  I see beemer boneyard has a Noris but even that is still pretty pricey.
2. Where can I get a new fuel level sender?  Mine is super corroded and the wire connections are also nasty so I’d like a new one.  Beemer boneyard is out of stock.

EDIT: How do I know if I really should replace the fuel pump?  Wondering if I should put 12V to it and see if it actually still pumps water or not.  And if yes, just put it back in?
  • San Francisco
  • 1990 K75S (in 1000 pieces)

Offline Martin

  • ^ Quintessential Motobricker
  • Posts: 4437
Re: Just picked up a K75 - need input on the plan of attack
« Reply #73 on: July 05, 2018, 12:24:00 AM »
A few inmates have been running Chinese pumps, with no issues. I've had mine running for coming up to 12 months, if it goes for another 12 months I'll order another as a spare. Apparently early Chinese clone pumps had issues but so far so good.
See http://www.motobrick.com/index.php/topic,10054.msg86054.html#msg86054
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline oneplustwo

  • ^ Motobrick Curious
  • Posts: 109
Re: Just picked up a K75 - need input on the plan of attack
« Reply #74 on: July 05, 2018, 12:31:08 AM »
Ah, nice.  Didn't come across that upon search.  For $24, I'll just order one and not bother with the old one.  Could be a spare I suppose!

I don't suppose AliExpress has fuel senders?!  :)

  • San Francisco
  • 1990 K75S (in 1000 pieces)