Yamaha SR250 Classic

Discussion in 'Old's Cool' started by oc_nightmare, Jan 18, 2010.

  1. oc_nightmare

    oc_nightmare Been here awhile

    Joined:
    May 11, 2009
    Oddometer:
    188
    Location:
    Leiria, Portugal
    There ya go, all finished (for now). The fuel tank just had a small coating of metal varnish because I love the color of the steel and it was the cheapest option:wink:
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    My girlfriend aproved it as always:freaky
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  2. regal7point5

    regal7point5 n00b

    Joined:
    Sep 23, 2012
    Oddometer:
    2
    The bike is looking good! I missed out on a deal of a XT600 just last week...darn!

    One more question on the SR312...did you use the YFM350 valvesprings too, or just reuse the stock SR250 springs? Not sure if one is better/stronger/different than the other.

    I am slowly gathering parts and should be getting some real work done on mine soon!
  3. oc_nightmare

    oc_nightmare Been here awhile

    Joined:
    May 11, 2009
    Oddometer:
    188
    Location:
    Leiria, Portugal
    I thought about the valve springs when I did the engine and assumed that because the warrior's not a revy engine, the valvesprings would be about the same compared to the stock SR ones.
    I'm doing a welding certification (P24 steel this time) and haven't been home in a long time and now I really miss my big thumper:cry

    When I start earning some money, I'm going to redo the whole frame again (make space for an airbox and make a craddle) like I really mean it, stay tuned :evil
  4. Bvander

    Bvander n00b

    Joined:
    Jul 28, 2013
    Oddometer:
    4
    Location:
    Gold Coast Australia
    Nice work on the bike mate. It has been a bit of a guide for me to start planning some mods to mine. Thought I would sign up and say thanks for the info.

    I am planning to stick a 83mm piston in which will give a 305cc displacement. I was wondering if you had to bore out your case to fit the 84mm piston in?
  5. Valleyrider

    Valleyrider I Survived The '60s

    Joined:
    Apr 12, 2007
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    1,896
    Location:
    Idaho Panhandler
    Very nicely done!!
  6. oc_nightmare

    oc_nightmare Been here awhile

    Joined:
    May 11, 2009
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    Location:
    Leiria, Portugal
    No problem mate :)
    yes, i did have to bore the case :)
  7. Bvander

    Bvander n00b

    Joined:
    Jul 28, 2013
    Oddometer:
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    Location:
    Gold Coast Australia
    Damn, I was hopeing to get away without doing it.

    Maybe I will have to go a smaller piston haha. Trying to do it without modding the case.

    How is the frame holding up with the 600 in it?
  8. Bvander

    Bvander n00b

    Joined:
    Jul 28, 2013
    Oddometer:
    4
    Location:
    Gold Coast Australia
    After a bit of research and chatting with engineers the largest size recommended that I have found can be done without a case bore is 76.5mm. I am going to try for 77.

    I was wondering where you got your new head gasket from, or did you simply buy some copper sheet and cut your own?

    Thanks again for the help mate.
  9. oc_nightmare

    oc_nightmare Been here awhile

    Joined:
    May 11, 2009
    Oddometer:
    188
    Location:
    Leiria, Portugal
    it is a simple procedure, boring the cases, the same person that will bore your cylinder can easily do it ;)

    the frame is holding up just fine, there are some problems I wish I had done things differently but this was the fist time, maybe one day I'll do another one.

    where in the Gold Coast are you from? I was in Mermaid waters last year. Done 4000km in a postie :) great country, I really fell in love with it and I really hope to live there someday as a pipe welder :)

    btw, the gasket was from ebay, there is a guy in the US that has the template for the SR 250 engine's gasket and I just told him what was the diameter and thickness. Don't remember his name anymore though :(
  10. 10ecjed

    10ecjed Been here awhile

    Joined:
    Dec 15, 2011
    Oddometer:
    292
    Location:
    Frederick, MD
    I have a question for you. When you were running the 250/310 engine you were still using the stock carb. Was it a BS34 Mikuni? I am helping a friend rework his stock carb on a SR250. I have the BS34 on my XS650 and his look identical except mine has a rubber plug over the pilot jet. Did yours have that. Any help would be appreciated.
    BTW your project is incredible. I am going to start my XT550 rebuild now.
  11. Bvander

    Bvander n00b

    Joined:
    Jul 28, 2013
    Oddometer:
    4
    Location:
    Gold Coast Australia
    Thanks mate, I am from Benowa, right near mermaid waters. After getting pricing for case bores and such I started thinking a new project might be in order. After that things fell in to place and I am picking up an 83 GS750 thisarvo.

    Plenty of work for boat builders around the Gold coast, Lots of Tinny builders are based here. Might have to get into aluminium welding lol.