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Fixing up a DT3

Discussion in '2 smokers' started by Chips900S, Jun 2, 2020.

  1. Chips900S

    Chips900S Been here awhile

    Joined:
    Jul 13, 2017
    Oddometer:
    135
    Location:
    Central VT
    Hi all! Recently dug a ‘73 DT3 out of my friends barn and am fixing it up for her to learn to ride. Currently got it running and riding fine, but man it kicks back like a mule when you kick start it. To the point of me just bump starting it down my driveway because I don’t want to break an ankle, let alone let my girlfriend try to do it. So my question is am I doing something wrong? I read that if you have it over advanced they tend to do this but I have the timing set at 3.2mm BTDC, like the spec says, and the mark and the pointer line up on flywheel when I do it. Am I missing something or was this something they tend to just do? It’s pretty awful....

    pic for laughs it’s quite a ugly duckling but hopefully a good bike to learn how to ride on, other than that issue it’s a fantastic little bike...
    #1
  2. Chips900S

    Chips900S Been here awhile

    Joined:
    Jul 13, 2017
    Oddometer:
    135
    Location:
    Central VT
    35C65547-10F5-4119-A311-860D597C6AA7.jpeg
    #2
    sidetrack one and mikeysduck like this.
  3. Tim McKittrick

    Tim McKittrick Long timer

    Joined:
    Dec 29, 2003
    Oddometer:
    2,380
    Location:
    Wasilla Alaska
    The problem is that the bike is at full advance all the time, so a timid kick will allow it to fire and try to spin backwards, kicking you back. The 250's are bad- the 360's are worse. Add to this the weird angle the kicker has and it's tendency to slip off your foot and you will see why it is foolishness to attempt to start one of these without really heavy boots.

    The 175's had an advance mechanism and are super friendly and easy to start, and the very first 360's had a similar system that instantly broke and its nearly impossible to find one now. Yamaha simply made all of their bikes fixed ignition and called it good- even the TZ road race bikes.

    I converted my RT2 360 to a Powerdynamo ignition and 12v charging system- but the ignition timing remains the same. It starts a little easier as the spark is hotter, but you still have to really boot it- you need to impart enough energy to keep the flywheel spinning the correct direction as it fires.

    You might try retarding the timing a little- the factory spec is intended for decent fuel anyway and if you run this bike at steady highway speeds it will get too hot. You will feel it loose a little power and begin to go soft as the cases heat up and the charge density decreases- this is your warning to back off the throttle and let it cool off. I'd back it down to the 2.8-3mm range and see how it runs- it should start a little easier, but you still need to give it a meaningful boot.

    My Dad bought two RT2's new in 1972, one for himself and one for my Mom. Both were new riders and they couldn't have picked a worse machine to begin on, if only for the starting difficulties. My Mom abandoned hers in a fit of rage in the middle of an intersection after it had clicked her back one too many times, walking home and telling my Dad that the bike could come home or she could, but not both. He sold it to a coworker- it had under 300 miles on it.
    #3
    spokester and Chips900S like this.
  4. Chips900S

    Chips900S Been here awhile

    Joined:
    Jul 13, 2017
    Oddometer:
    135
    Location:
    Central VT
    Wow thanks for the insight! I actually did just that yesterday, retarded the timing and now it kicks thru just fine. I noticed the heating up like you mentioned so I adjusted it a little more to get it advanced but still behind the 3.2mm mark and now seems pretty good.

    currently dealing with a difficult cold/warm start, carb is totally clean but I’m thinking I just haven’t learned the proper way this bike likes to be tickled to start. If I put it in 3rd and roll it down driveway with throttle open a bit she starts right up and stays running/idling fine. It’s just the initial start, not enough fuel I think, even if I choke it. I’ll fiddle with it today and see what I can find....
    Thanks! Chip
    #4
  5. ausfahrt

    ausfahrt mach schnell Supporter

    Joined:
    Apr 17, 2008
    Oddometer:
    3,555
    Location:
    Vermont
    Cool bike. I learned to ride on a Suzuki TS-185 and my buddy rode a DT-250 that looked just like yours and he would always leave me in his dust.:D

    I've been looking for one. Good find.:thumb
    #5
    Chips900S likes this.