RM250 dies when hot

Discussion in '2 smokers' started by JGroves, Sep 20, 2012.

  1. JGroves

    JGroves Late

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    nt
    #1
  2. anotherguy

    anotherguy Long timer

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    Coil or CDI box.
    #2
  3. SM Crank

    SM Crank n00b

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    Strip the carb, sounds like it pulled some crap out of the bottom of the tank when you ran it dry.

    Happened to me!
    #3
  4. anotherguy

    anotherguy Long timer

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    You can start the bike,let it idle and heat the CDI or coil with a hair dryer and see if it fails when it gets hot. Don't overdo the heat you can kill the component.
    #4
  5. PSchrauber

    PSchrauber Been here awhile

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    I guess when you simply replace the plug the bike will run again.
    #5
  6. third eye

    third eye back road loon

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    I would totally go through the entire fuel system and make sure everything is cleaned out.
    #6
  7. Shocktower

    Shocktower Long timer

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    And since it's got some age on it I would also put a new set of main seals, probably worth the 16-20 bucks instead of the 200+ to rebuild a blown up 2 stroke, also claean the carb, i am pretty sure the piliot jet is gummed up too JMHO :D
    #7
  8. wfopete

    wfopete Suffer Fools; Gladly!

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    Ditto on what has been said. Moving targets can drive you nuts. Most likley the fuel system but maybe not. Start with the basics first (fuel, comp., spark). Check the grounds for your ignition!!! It's an old bike and corrosion can be everywhere. Clean, tighten bolts, screws, put on lock washers to get a good bite into the frame. Might as well move on to a Comp. test or leakdown test before diving into the crank seals. If it turns out to be crank seals or ignition labor and parts may not be worth the fix. If you need new ignition parts, OEM can be SOL. A PVL or other after market ignitions can be upwards of $500!

    Good luck.
    #8
  9. 4badboyz

    4badboyz Been here awhile

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    had the same kind of issue with my cr250 until I changed the coil. very frustrating to figure out.:huh
    #9
  10. RodT

    RodT Been here awhile

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    just a thought, check the tank vent, sometimes this is the problem. I had a new ski-doo, and it would run fine for a little while and die, would not start until it sat for a while. It finally siezed the motor and that's when we found the vent tube was kinked . caused a serious lean condition.
    #10
  11. larryboy

    larryboy Chopper Rider

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    Uhm, you ran a two stroke out of fuel...in other words, without lube for the piston. Melted rings and a scored bore is my bet.
    #11
  12. RodT

    RodT Been here awhile

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    I hope you are kidding ??? I run chainsaws for a living and trust me, they run out of gas alot!!!!Runnig out of gas in a 2 stroke dosen't hurt a thing.:norton:norton:norton
    #12
  13. motomark39

    motomark39 I reckon so

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    Take it off, have it tested
    #13
  14. D.T.

    D.T. Difficult but useful

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    Yeah, what they said.

    I'd pull the plug when it won't start and look for spark. I've seen the reisitors corrode in the caps too.
    #14
  15. 81cr450

    81cr450 Been here awhile

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    Cheap answer is always the best to try first

    Strip the carb, sounds like it pulled some crap out of the bottom of the tank when you ran it dry.

    "just a thought, check the tank vent, sometimes this is the problem. I had a new ski-doo, and it would run fine for a little while and die, would not start until it sat for a while. It finally siezed the motor and that's when we found the vent tube was kinked . caused a serious lean condition."

    "I'd pull the plug when it won't start and look for spark. I've seen the reisitors corrode in the caps too."

    In that order.

    Old bike should really have fresh main seals, $20 for a flywheel puller, $20 seals. It dont cost a mint to ride old bikes just common sense & not throwing money away on guess's. Use the process of elimination on the cheaper fixes especially where you can get it to run. Should be a blast once you get it sorted, I sure wouldnt mind a 90's RMX250 myself
    #15