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Boyer Bransden timing on 76 ?

Discussion in 'The Garage' started by hotrdd, Jan 31, 2011.

  1. hotrdd

    hotrdd XS650 Junkie

    First post here - I have just completed installing the Boyer Bransden Ignition on my 1976 Yamaha xs650 project bike according to the instruction sheets but despite my best efforts the timing seems to be way off and I can't get the bike to even idle so that I can set the timing. The bike was running, rough, before I installed the ignition system but would at least idle. I have confirmed that I have good spark and fuel.

    Since I don't currently have a good battery I was using an old battery but had large jumper cables from my truck connected so that I could try and get it up and running. Unfortunately trying to use a timing light was just way to sporadic.

    Couple questions.

    1) I centered the white dot on the trigger magnets below the magnetic pickup plate with the timing set at the total lead position. But the timing seems to be off is it normal for this to be out by 30 or 40 degree's???

    2) When the trigger magnet rotates I can feel it making contact with the bars on the magnetic pickup plate, is this normal at first?

    3) Is there a chance that I am off by 180 degrees?

    4) What do you recommend for a battery, looking for something good?
  2. hotrdd

    hotrdd XS650 Junkie

    FYI - reply from Boyer Bransden Tech

    If the magnets are touching the pole pieces check the rotor is fitting in the old bearing bush for the advancer shaft, it will be a snug fit. If this is OK then see which pole it is touching and remove a little from it so it clears.

    If it is timing more than 10 degrees out I suspect the B/yellow and B/white wires are swapped.

    Hope this is of help.

    Tech Dept

    Boyer Bransden Electronics Ltd
  3. XSLeo

    XSLeo XS650 Guru Top Contributor

    Hotrdd, you will be a handy addition to the board. Lots of guestions about the Boyer system.
    Welcome to the board.
  4. hotrdd

    hotrdd XS650 Junkie

    Thanks, I've been toting around this bike for ten years now and am finally ready to finish thefinal bits and get iton the road this year. I'll post some pictures one of these days. Hope to contribute but also get lots of help.
  5. pumps

    pumps XS650 Junkie

    hotrdd-did you get it timed ok after all? I need a new battery too and most likely will get an AGM sealed type battery. In the past I have had an issue with a non-sealed battery dripping acid on mufflers on another bike. I have new mufflers to put on this one and that ain't gonna happen. By the way Welcome!
  6. hotrdd

    hotrdd XS650 Junkie

    I haven't had a chance to play with the timing any more but hopefully I get some time later this week. I'll probably get. New seal battery right away to take that outof the equation.
  7. tx650

    tx650 XS650 Enthusiast

    If you stick to the installation guide that comes with the unit then you have obviously either done something wrong or their is another fault,I put my money on the battery/charging system which is already covered on here.
    These bikes need a good charged battery to work properly and just a small point is that make sure the overflow tube is still in good condition and connected.
    I was wondering what all the discolouring was and I discovered that the tube had fallen off.I run them all the way down the centre frame tube past the centre stand hookups.Zip ties are your friend.Take Care.LTR RTL.
  8. hotrdd

    hotrdd XS650 Junkie

    Thanks, I'm going to double check everything tonight and then try and find a decent battery. I stopped at a few stores after work today but they all just carried the regular batteries. I'm looking for something sealed if possible. Though I already have an overflow tube fitted through the frame and just off the ground. Will keep you posted.
  9. hotrdd

    hotrdd XS650 Junkie

    So I wasn't able to find a battery tonight so I was still using heavy jumper cables from my truck. BUT I did confirmed that the b/yellow and b/white wires were connected correctly. However according to the installation guide with all the pictures I may have had the plug wires from thecoil switched. So I switched them back, confirmed everything was set according to the instructions and it still didn't start. Even though I have fuel and spark. I'll need to get a good battery and confirm my results with that. Question though despite the bike not idling should I still be able to use the timing lightwhile cranking? At first I had a few light flashes and then it just flashing despite having spark. I took it off the Nike and put the light on the truck and confirmed it was working.
  10. hotrdd

    hotrdd XS650 Junkie

    Stupid question BUT, if I have spark and I have fuel shouldn't the engine run? Obviously the timing could be way off but outside of that, if I have spark is there anything else electronic that needs to be powered up?
  11. grizld1

    grizld1 Grumpy old man Top Contributor

    You can't use the timing light while cranking; the Boyer is strobed with the motor wound up until the ignition reaches max advance. Although the instructions specify aligning the white spot with the engine rotated until timing marks are at full advance, guys often miss this and try to set the spot with the marks in the idle position. Also, the white spot gives only a ballpark setting. Try setting the plate with the spot a bit off-center in either direction and see if you get fire.
  12. hotrdd

    hotrdd XS650 Junkie

    I have the mark set at full advance and then set the white mark. But even if I slowly rotate the magnetic pickup plate while cranking I'm not getting any firing. I'm going to pick up a new battery to make sure that it's not battery related
  13. triniriderz

    triniriderz XS650 Enthusiast

    Im just sorting out a Boyer ignition at the moment and for some reason I remember someone saying to make sure you are running NGK iriduims not the standard plug.. Could be a bit of useless info or could help I dont know??
  14. hotrdd

    hotrdd XS650 Junkie

    I thought about that but didn't want to install the new plugs until everything else was sorted out. I can be cheap that way :). Guess I could throw them in and see if there is any difference.
  15. XSLeo

    XSLeo XS650 Guru Top Contributor

    Use the standard plug for set up and testing the ignition and carb tuning. No sence in fouling out $8 plugs. The $4 plugs will be fine.
  16. I use a Boyer ignition on my 73. I just aligned the mark on the crank to the "F" mark, and set the Boyer trigger magnets to the white dot in the hole. This was enough to get it started. Then I used a strobe light to set the full advance.

    I had to fix a bad main bearing, a year ago and when I put the engine back together I screwed up and did not get the shaft for the Boyer trigger magnets much more than finger tight. I thought I was Ok, but about a week after I was back on the road, under wide open throttle everything slipped, the timing went to hell and I coasted to a stop. It was like I turned the key to off. When I finally found what was wrong, the timing had not slipped much, but it was enough to wreck a nice ride.
  17. hotrdd

    hotrdd XS650 Junkie

    Good news – After setting everything back to regular configuration, getting a new battery and changing the plugs I was able to get the bike started. But I wasn’t able to keep it running. I noticed that once of the plugs was not sparking. However when I swapped in the Iridium plug I can’t say I noticed a huge spark. So how can you test the coil to make sure you are getting the proper output? I think my other problem is that the chambers were flooded with fuel after a few attempts and now I need to clean-up the carbs and get them re-tuned. Is there a good thread on that? I’m a newbie when it comes to Carbs and scared of them 

    So the problem was either battery or a bad plug, though I’m not convinced the coil is spitting out enough power. How can I test?
  18. XSLeo

    XSLeo XS650 Guru Top Contributor

    You need to check the ohms of the primary and seconary sides of the coil. Being a Boyer I don't know what the ohm spec is for your coil. If you have the right ohms and no shorts to ground then the coil should be ok.
  19. hotrdd

    hotrdd XS650 Junkie

    FROM:Boyer Bransden Electronics Ltd

    Yes this is the micro power for XS650. Try running the ignition + on the ignition coil via a 10 to 15 amp fuse direct to the + on the battery. The old ignition wire will feed the box only, we have had some trouble with poor wiring and switches on this machine and the ignition coil requires high current pulses for very short periods for it to work.

    Hope this is of help.

    Boyer Bransden Electronics Ltd
    Frindsbury House
    Cox Street
    ME14 3HE

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