Installing an Acewell speedo/computer on an airhead --

Discussion in 'Airheads' started by bpeckm, Nov 23, 2009.

  1. batoutoflahonda

    batoutoflahonda Long timer

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    Yeah, it's pretty simple once you get your head around it. I used Delphi weather packs and did away with the Acewell plugs. Partly because I was adding a whole bunch of other stuff, 60+ wire terminations. Only had 2 issues. Got the turn signals crossed and the tack wire at the OEM instrument cluster didn't go any where.

    The benefit with swapping out the acewell plugs is 1) if a miss wire occures you just move a pin into another slot. No having to redo solder etc. 2) troubleshooting is a breeze. Just disconnect them and poke around. Try to group them together tho. One connector for power/ignition, one connector for the first acewell *group* etc. Then number the connector plugs per the acewell wiring diagram. So the first group is 1 then the Delphi sockets are lettered A,B,C etc. This also helps get rid of the Acewell middle connection if desired. So do some poking around and see if there are other connector kits to your liking, if this is the way you want to go. Drop me a line if you need help with the Delphi stuff.

    The whole connector thing cost 30 bucks with the crimper.
  2. bill42

    bill42 Old-School BMWs

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    here is a nice photo I took last night.

    [​IMG]
  3. MIOB

    MIOB Long timer

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  4. bill42

    bill42 Old-School BMWs

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  5. tete

    tete clown shoes

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    Here is where I stand. Everything works perfect except forthe speedometer. I wired this up and no results still. I tried splicing the white wire and grounding it. Also tried connecting to blue which was dumb because that's for the fuel indicator. Also tried white the regular way by connection it as pictured [​IMG]
    Acewell 2853

    [​IMG]
  6. tete

    tete clown shoes

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    Also for what ever reason I do get speed at times using the plug harness as my drawing shows. All the sudden it will flash a speed for a couple seconds them it will read zero again. Rpm works fine, blinkers etc. just the speedo
  7. batoutoflahonda

    batoutoflahonda Long timer

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    I did a solder splice on mine and the mph were very erratic. Assumed it was the splice, so I ordered another sensor from Baja Designs, 20 bucks. That fixed it up. BUT, not sure if it was the splice or the sensor.

    What you could try, is take the supplied wheel sensor and just tape (ie. scotch) the magnet to the rim, then tape the pickup to ?. Then see if you get any indication. That will tell you if it's the sensor or the instrument/wiring.

    Actually, maybe you could just tape the magnet to a drill chuck and hold the pick up close enough to get a reading?
  8. tete

    tete clown shoes

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    good idea. will do over the weekend.

    Thanks
  9. mattcfish

    mattcfish R90X

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    Putting an Acewell 2853 on a 1975 R90/6. It appears my wiring is more closely matched to a 74. I've got everything figured out accept....... I have a solid black wire going to the #10 terminal on the square pod plug. Does not show on my Climber or Haynes manual. Anyone know it's purpose?
  10. bpeckm

    bpeckm Grin!

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    According to my old notes, Pin 10 is the tach sensor (which is also the points "ground").....The older bikes of course have a mechanical tachometer, but the later bike with an electronic tach simply use the ground side of the points (or later bikes, the hall sensor)

    [​IMG]


    :eek1
  11. mattcfish

    mattcfish R90X

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    Thanks, makes since, but why does the points ground go into the instrument pod on a mechanical tach bike?
    Does it serve a purpose there, or was it pre-wiring for the evential intro of electronic units?
  12. batoutoflahonda

    batoutoflahonda Long timer

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    If the speed indication quits but every thing else works, I suggest pulling over and taking the sensor out to have a look. On a recent trip this happened to mine. Pulled it at the next gas stop to check that it hadn't bound up.

    It seems that there is a pin that holds the square drive part of the sensor that worked it's way out. It broke apart the pickup assembly and the square drive part was twisted. I removed these parts to keep from damaging the transmission speedo drive and put the sensor housing back in to help seal the hole.
  13. mattcfish

    mattcfish R90X

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    I'm running a 32/11 final drive. Has anybody set up an Acewell with the transmission mounted sensor to work with the tall gears? What number did you use for the tire circumference since you need to adjust for the gear ratio? Post #441 mentions using the 1480 setting for a 34/11. I assume I need a bigger number than that.
    If someone has already listed this figure I apologize.
    It would be nice for this thread to have a list (given the average rear tire size of an airhead, my measurement was 82 1/8") of which setting works with each ratio.....for those of us using the S-11 sensor, that is.
  14. mattcfish

    mattcfish R90X

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    OK, I got the formula off the Acewell forum. http://acewell.com.au/forum/viewtopic.php?f=5&t=46 My 26.1" diameter tire (82.125" circumference) combined with a 2.91:1 (32/11) gear ratio at the final drive) will give me a ballpark "c" setting of 717. A long way from 1480 from the previously mentioned post. Not sure what he's talking about. According to Acewell, if you're using a transmission mounted sensor you need to divide the tire circumference (in millimeters) by the number of times the wheel rotates per sensor revolution.
    82.125"=2085.975mm
    2085.975 / 2.91=717
    We'll see if that's close
  15. mattcfish

    mattcfish R90X

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    Ignore everything I previously said, c= 1425 or very near abouts on a 32/11 equipped bike. I arrived at this through trial and error on the long ride to the MOA rally from B'ham to Salem via Eastern Wa.
  16. bpeckm

    bpeckm Grin!

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    I don't remember the numbers, since it has been years now, but I did the fine-calibration by riding by one of those police radar "Your speed is ..." and then stopping, going into the Acewell, and changing it. Took three tries, but it ended up nailed Dead-ON.....

    :D
  17. bill42

    bill42 Old-School BMWs

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    Yup. I tried to figure out the math and gave up. I don't think I had to divide by two for my transmission pick-up. The default from the Acewell out of the box was around 10 mph off on my R100 and I found the easiest way to calibrate it was to mount my iPhone/GPS to the bike and simply compare accurate GPS speed reading to the Acewell. Took about 5 minutes and 4 estimates to adjust. For me I think the number was around 1370 ish.
  18. bpeckm

    bpeckm Grin!

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    My point is: no need to do math! Just change the number that is in there up, re-run the speed radar, and see if you need to go further up, or down, or whatever... it's call "trial and error,,," :evil



    ...all you need is patience and persistence....


    :D
  19. some_guy

    some_guy Been here awhile

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    I figured mine out this way...don't know if its right but it ended up close enough.

    kph ration on snowbums site (linked many places here) for my final drive is 0.691. One rotation of my tire measured at 2001mm. I set C = 2001 x 0.691 so 1382 and some change. Seems to be within 5mph or so.
  20. mattcfish

    mattcfish R90X

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    Remember, this is "Old School". Ain't got no Gad Damn GPS.
    Drove next to the "cages" for awhile and got an idea of what 65 to 75 mph was.
    Kept re-adjusting to what felt right. Happened to pass one of those radar signs as I passed through a town. It said I was doing 33, looked down at the speedo...33mph....howlalooyah!