Page 1 of 4 123 ... LastLast
Results 1 to 10 of 31

Thread: xb12R engine swapped into xb12ss

  1. #1
    Junior Member
    Join Date
    Mar 2020
    Posts
    15

    xb12R engine swapped into xb12ss

    I am trying to help my daughter with her bike that ran hot and developed an knock in the bottom end
    we found a donor salvage bike and I was able to start the salvage bike but then at some point I could not start it but figured that's ok it was a wiring mess in the front of the bike anyway and shrugged it off as a fluke and was happy that it sounded good when it ran
    Put the engine in her bike that went all quite well
    Tried to start it and found that there is no spark and no neutral gear switch light
    I swapped the high voltage coil put 1 sparkplug in it and plugged it in and turned engine over, still no spark
    Now I am thinking the camshaft sensor on the donor engine died? I am going to check all the plugs again whether I made a mistake by not fully engage plugs or something
    Dont even know where it is and if it is on the right side of bike under the label close to crankshaft then that looks complicated almost like I have to drop engine again because pipes are in the way? Also swapped the race ECM which are identical on both bikes
    Has somebody some input on this quist?
    thanks

  2. #2
    Senior Member 34nineteen's Avatar
    Join Date
    Mar 2015
    Posts
    1,765
    What year is the bike for starters?

    I would put a voltmeter or test light on the plug going to the coil first to see if itís even getting voltage to the coil. Page 4-70 has a diagram calling out what the wires on the coil connector do, so it should be an easy test.

    Also, depending on the year, you may not have the cam sensor wired correctly. Page 4-71 has a diagram of the wiring of the CPS. Page 4-95 has some excellent info on the cam sensor as well.

    Or maybe a bad sensor is why someone parted out the bike the motor came from in the first place.

    Or depending on the year of the bike/motor you may have a crank sensor?
    Last edited by 34nineteen; 03-30-2020 at 10:08 PM.

  3. #3
    Senior Member 34nineteen's Avatar
    Join Date
    Mar 2015
    Posts
    1,765
    Also, check the neutral light switch to make sure the wire isn’t broken or grounding out. That can cause all sorts of weird issues. They cover testing on page 7-63 of the service book. If it is faulty, you can grind down a wrench or socket to make a special tool to remove it with the pulley in place.

    If your daughter is a shorter rider, I will trade you my 2004 S with Scg (factory lowered) suspension. It’s a tiny little bike!

  4. #4
    Junior Member
    Join Date
    Mar 2020
    Posts
    15
    The donor bike xb12r was in an accident and was an insurance write off and is a 2003
    My daughters bike is a 2006 XB12SS everything seems the same as far as wiring around engine and even exact same ECM module.
    I do have a dongle to look into ECM except I am waiting for my daughter to show up with a android device, I 've got windows or Iphone and dont think there is a app for them is there?
    Also gonna check as much as I can , I do even have a oscilloscope but I dont have that book you refering to
    Thanks for hints 34nineteen and by the way my daughter is considered tall. Never seen a Buell in my live as I know it till she came home with one
    I had a honda for the longest time and last year got myself a 2005 HD 1200 sl custom thinking to slow down a bit at my age and now everything seems to speed up LOL
    oh and what I also found is that if I unplug the sensor on bottom of airbreather box or the module for the exhaust valve on top of breather it wont start (dont need it with after market pipe but need to be plugged in at this point (thinking maybe I can ddisable it? but that is not my problem right now)

  5. #5
    Senior Member Cooter's Avatar
    Join Date
    Dec 2012
    Location
    Crawling up your skirt
    Posts
    7,666
    Total guess would agree with 34:19 and the CPS or the CPS haha. Looking it up should be as easy as reading that section of both manuals. You can get them for free at Buellmods.com or Buelltooth.com.
    '03 had a different speed sensor, trans output sprocket, as well. Yes, the ECM boxes are interchangeable, but the programs/firmware are most likely NOT the same.
    Use the ECM that came with the R engine, and diagnose the bike FIRST. The ECM is a solid state, gel filled box that RARELY has an internal problem. Guessing and fiddling with the ECM will only give you many hours of chasing your tail.

    You can use the Bluetooth dongle (Buelltooth.com) to wirelessly communicate to the free program ECMDroid (GooglePlay store) and help considerably with wiring and sensor diagnosis. You will need an android device. It is WELL worth the $30 burner phone or tablet (no SIM needed) for simplicity of use, adjustments or any future datalogging. It is a TOOL that should be in your Buellbox(TM), right next to a T27 and and a 19mm axle hex.

    RTFM

    Besides, it's probably just out of gas LOL

  6. #6
    Senior Member 34nineteen's Avatar
    Join Date
    Mar 2015
    Posts
    1,765
    Ok, cool. Sounds like everything should be easily swappable between the two.

    I would continue to use the accessories from the Ss and just the bare motor from the R.

    Since it is an 03, like Cooter mentioned, the output sprocket is different. You will need to change that to an 04-up style or you will have problems even after you get it running.

    I’d also check to make sure the coil is even getting current from the plug when the motor is turning over . If you are getting current, you know what side your problem is on (unless your timing is way off).

    Also you may want to move the CPS from the Ss to the R motor. You will have to disassemble and reassemble the Deutsch connector (it’s easy but needs to be done specifically-follow the procedure in the manual or you will really get messed up!) to get the CPS out of the cam cover. That’s where i would start. If that circuit is getting juice, it will fire the coils when the rotor triggers the CPS. I once left the ignition on while working on one of my XB’s timing. As I moved the plate to set the timing, I must have triggered a coil and there must have been some fuel in the cylinder, cause she went boom when I moved the plate. Luckily I was able to save those shorts.

    Dammit Cooter, you know full well there is a difference between CPS and CKP! grumble grumble. Lol
    Last edited by 34nineteen; 03-31-2020 at 12:55 AM.

  7. #7
    Senior Member
    Join Date
    Aug 2009
    Posts
    606
    Buell didn't make a 12 in '03. Might be an '04. Picture might help.
    Matt

  8. #8
    Junior Member
    Join Date
    Mar 2020
    Posts
    15
    thanks a lot guys I'll let you know how things go from here on
    I read on donor bike frame jul '03, I double check it again (I don't have papers, no need 'cause frame/tank were dinged among other things), also I actually measured at some point sort of quickly the diameter of the belt drive pulley, they were the same was my conclusion, (did not count teeth)

  9. #9
    Senior Member Cooter's Avatar
    Join Date
    Dec 2012
    Location
    Crawling up your skirt
    Posts
    7,666
    The pulley is narrower in '03, but sounds like an '04 with a build date like that. Good call Loose1, I totally missed that

    Don't ignore the speed sensor difference, I'm not sure of that split, but they are totally different voltages and can cause bigger issues than the speedo just not working.

  10. #10
    Senior Member squidbuellie's Avatar
    Join Date
    Jan 2011
    Posts
    2,002
    I glanced through your post. I have a idea of what’s going on... but first I need some quick info.

    1) vin to your motor... just to know exactly what you are working with.

    2) I did see you mention that the ecm’s looked the same but quick question do they both have three wire inputs?
    Two big plugs and one single wire that connects in between?

    2) if everything is right you can do a quick cam sensor check without taking anything apart except the timing plug. Lift the rear tire off the ground and put the bike in 5 gear with The bike “OFF” turn the rear wheel clock wise(forward) till you see the timing mark in the case sight hole.
    Then turn the bike “ON” and turn “ON” the run button then roll the tire a half turn forward then a half turn counter clockwise (backwards) to where the tire dose a forward rotation 180 deg and backwards rotation 180 degs... depending on how it’s timed dead on,retarded or advanced you should hit top dead center and the fuel pump should prime.

    You can also do this with the bike on the ground if you have two people one with a flashlight looking for the timing mark the other rolling the bike..

    Also to play it safe do it one time then rotate the crank 360 and do the same thing again just to make sure you have the bike at top dead center.

    And just a heads up the cam sensors do go out but usually give plenty of warning... ie bike will start but after a certain temp will shut off.
    I myself have had 3 Fail on different bikes.

    : one last thing when you turn the switch to run the fuel pump will turn on and prime the fuel system then shut off then rotate the rear wheel and it should come on again for a couple of seconds.



Page 1 of 4 123 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •