TY250 project

Discussion in 'Trials' started by Junglejeff1, Nov 1, 2018.

  1. Junglejeff1

    Junglejeff1 Long timer

    Joined:
    Oct 20, 2016
    Oddometer:
    3,846
    Location:
    Upper Michigan
    The drum does not look worn.Considering the pads do not actually span the whole thing i would think there would be a ridge in there if they were.It works decent now but i think it can be better.
  2. Portlandtyist

    Portlandtyist Been here awhile

    Joined:
    May 10, 2014
    Oddometer:
    130
    Location:
    Portland Oregon
    Excellent project.
    I am trying to time my 250A after new points mounted. But my dial Indicator will not function due to frame.
    Any ideas on a bracket (as in TY250A’s shop manual) to use having removed the head?
    Or, perhaps knowledge of a smaller dial indicator that will work through spark plug hole?
    Thank you sirs.
  3. Twin-shocker

    Twin-shocker Long timer

    Joined:
    Jan 28, 2012
    Oddometer:
    1,779
    Take the head off measure piston position with digital vernier, put timing marks on flywheel and time with strobe light. This is worth doing to any points trials bike, not quite as accurate as a dial gauge but fast and easy and fine for trials motors.
    Junglejeff1 likes this.
  4. Junglejeff1

    Junglejeff1 Long timer

    Joined:
    Oct 20, 2016
    Oddometer:
    3,846
    Location:
    Upper Michigan
    Late update.Installed electronic ignition.Found timing light pretty useless with stock timing mark.Ended up adjusting by how well it would run (just a wee bit advanced of center of slot).Also could not get front brake working to my liking even matching pads to drum.Installed a 77 tt500 wheel with a 1980 yz front twin leading brake.Stops much better now but took a lot of messing around.I had to tig weld a lug on left fork and machine about 1/2" Off axle lug.I am finding oko carb a little bit finicky to weather but not terribly bad.Bike runs great and got its 1st reward taking 3rd at smagical rock.Only 4 vintage riders all. 20190822_121916.jpg 20190824_221058.jpg 20190818_140129.jpg
    yamty175, Huzband, Buschog and 2 others like this.
  5. Junglejeff1

    Junglejeff1 Long timer

    Joined:
    Oct 20, 2016
    Oddometer:
    3,846
    Location:
    Upper Michigan
    Also on the lower coil there is a metal pointer that you line up with mark on flywheel. Out of 3 ty,s I have adjusted that pointer was about spot on.Can use a multi meter,buzz box or timing light.
  6. UstaKood

    UstaKood Been here awhile

    Joined:
    Feb 5, 2016
    Oddometer:
    312
    Location:
    Michigan
    In the past , I found that a longer rod for the dial indicator was required and removal of the exhaust and 2 motor mount bolts ( front and top rear ) allowing the motor to tilt down allowing access without full removal . Last time I set it with the head off and magnetic base indicator and confirmed pointer location .

    Getting it set as close as possible to its 3.4 mm btdc gives it the best overall performance .

    BTW Jeff , how are the emulators performing ?
  7. Junglejeff1

    Junglejeff1 Long timer

    Joined:
    Oct 20, 2016
    Oddometer:
    3,846
    Location:
    Upper Michigan
    I have not installed yet and may not bother.Between the new aftermarket springs and type f tranny oil(about 10 wt) they work well for trials riding.
    Brewtus likes this.