Mid 60's Bultaco Matador Project

Discussion in '2 smokers' started by tenorjazz, Feb 14, 2011.

  1. tenorjazz

    tenorjazz Been here awhile

    Joined:
    Mar 11, 2007
    Oddometer:
    267
    Location:
    Woodinville, WA
    I understand that the throttle will be an issue so will probably swap that out but the foot pegs are stock and have been told that they won't be a problem.

    I've never ridden trials before and never cared to much about competition. I do plan on riding it so figure however it goes it will be fun.

    The frame has been modified and swing arm was shortened so the rake and trail are not stock. The previous owner made these changes as well as adding a couple of other little trick features, including a quick release on the seat. Most of this doesn't mean a lot to me, it just happens to be what the bike is. But since I've built this bike for a friend of mine who does compete, after I've played around on it for a season of so, we'll upgrade the parts that aren't working so good and he should have a nice competitive bike to ride.

    This is the first bike I've ever built so I also wanted to experiment with finishing processes and besides I really like custom bikes more than stock. The frame, shocks, exhaust and most of the unpolished parts have been powder coated (a real learning process there). I learned how to polish aluminum and steel so it almost looks like chrome and wanted to do something different on the tank, so thought I would try pin stripping. Overall I'm pretty happy with the way it turned out, but like the second side of the tank better than the first, after figuring out a little more about how to handle the paint. I'm going to redo the tank after I get the bike back from the motorcycle show and I have an idea for something completely different, but still nowhere near to stock.
    #81
  2. buls4evr

    buls4evr No Marks....

    Joined:
    Sep 16, 2009
    Oddometer:
    2,318
    Location:
    Michissippi & Nuevo Mexico
    EVERYONE widens the pegs to 50mm if they are serious tenorjazz. They are also not long enuf. If you have not ridden trials don't start right out with a huge disadvantage like not being able to weight the pegs correctly. It is a big deal...trust me on this one:deal.
    #82
  3. tenorjazz

    tenorjazz Been here awhile

    Joined:
    Mar 11, 2007
    Oddometer:
    267
    Location:
    Woodinville, WA
    BTW... The tank has been sealed and the liner looks like it is well bonded. I plan on using ethanol-free gas so that should help with any gas tank problems.

    If I do plan on getting real serious with riding trials, I'll put the widest allowable foot pegs I can. I've ridden enough dirt to know this is a wise decision. It's just that I'm old enough to where I have enough body pains and don't heal very fast if I get broken, so I don't think I will be a serious competitor.

    Before I do anything else I need to see how well the engine runs and I can't check that out till next week, when I get it back from the show. In the end this bike goes back to Dave, the guy I built it for. I know he's itching to ride it.

    I'm already thinking about the two more bikes waiting for me to build, a 1966 Suzuki Bearcat and another 1965 Bultaco Matador.
    #83
  4. jdlothrop

    jdlothrop n00b

    Joined:
    Jan 9, 2012
    Oddometer:
    1
    I am still trying to set the timing on my '69 Matador.

    The prescription I am following is this:

    1. Set the points through the "window" at .016 at the hi point of the cam lobe.
    2. Set the timing by rotating the stator, (pulling and reinstalling of flywheel) until the light on my Bultaco box goes on indicating that the points are open at 3mm + - BTDC.

    The points are now precisely gapped at .016 at the highest point of the cam lobe. Checking the light indicates that the points are opening 3 and one half revolutions of the dial too early. So lets see - that would be 100 mm per revolution x 3 plus 50 mm = 350mm. Only off by 347 mm. So I need to rotate the stator plate to back the rubbing block off the cam a distance to allow the flywheel to advance enough to not engage the rubbing block 347 mm too early - not going to happen of course.

    All right - so set the points so they are opening significantly less than .016 which allows travel of the flywheel to trvael closer to TDC before the light comes on indicating that the points have opened. Now I have minimal point opening but the timing is close. Adjust the stator 1/4" - 1/2" travel to precision 3mm BTDC.

    One problem as I see it is that as the rubbing block wears the point gap gets less which means I don't go very far before I need to take everything apart again and reset points because they were set so close to begin with that they are now closed completely. Do the magnets line up because the stator was rotated - I believe by looking up through the window I can see that at the exacy moment the points open the magnets need to travel 1/4" before optimally located.

    Any help would be appreciated.

    Attached Files:

    #84
  5. PSchrauber

    PSchrauber Been here awhile

    Joined:
    Jan 3, 2011
    Oddometer:
    997
    Location:
    Summer: Kemiƶ, Finland; Winter: North Germany
    I never have done an ignition setting by your way with calculation of the TDC, as on newer Bultaco the piston pin sits not in the center of the piston also not recommended, (they changed the piston-pin position on later Bul's to reduce the tilt effect of the ultra short hub engines for the 350cc Sherpa's).

    As you wrote I also adjust at first the gap between the points. Then mount back the rotor.

    Now I search the TDC, for measuring the TDC i use a gauge, like this:

    [​IMG]

    Its a standard gauge with an extension pin that sits in a nylon shaft that you srew in the cylinder where the plug should be. The inner diameter of the shaft is slightly smaller as the shaft of the gauge so you can adjust the gauge to zero.

    [​IMG]

    (The washer is only for rough adjustment.)

    Now I mount a beeper to the ignition wiring, when it beeps I now know where the ignition point actually is, a lamp works too but you can only focus on one thing with your eyes so I like the peeper solution more.
    When the timing is wrong / not in the right distance before TDC I now take off the rotor and adjust the stator new.

    The beeper, (original Spanish Motoplat), or a standard Multimeter:
    [​IMG]

    Then I mount the rotor back again and do a second test, when it's right it's ok if not I have to readjust the ignition again, there is sadly no better way to adjust the stator. Normally I have to do two adjustments and the ignition timing is spot on, (You have to get used to this procedure, btw. even stated in the Bultaco users manual).

    [​IMG]


    When this is done I check the gap of the points again, if they are still in right spec's the job if done, if not you sadly have to do the hole procedure again, luckily this hasn't happend to me yet.

    Your timing specs are very forwarded to the one's I know from my model?
    #85
  6. redblk63

    redblk63 TacoDog

    Joined:
    Sep 12, 2012
    Oddometer:
    6
    Location:
    Pasadena, CA
    JDLothrop,

    You say "Checking the light indicates that the points are opening 3 and one half revolutions of the dial too early." I interpret that as the reading on a dial indicator which has been inserted into the spark plug hole.

    It looks like you may have misread your dial indicator gage. You say the timing was 350 mm BTDC, but the Bultaco engine has a 60 mm stroke! Any chance you were using an English units dial indicator gage where one revolution corresponds to 0.100"? That would make your reading 0.350", which corresponds to a believable 8.9 mm BTDC.

    Larry - Pasadena
    #86