See if you can solve my issue.

Discussion in '4-Stroke Engines' started by Rich S, Jul 31, 2012.

  1. Rich S

    Rich S New Member

    I have a 1983 Yamaha xt 200. Needed to be fixed up badly. It hasn't been started in a few years. So I started with the basics. When all said and done the bike won't start. I have fuel in the can. I recently cleaned the carb and it is working. I have 140 psi compression in the cylinder. I have a good spark coming from the spark plug. As I try to kick start the back if I am not open throttle I get no response. After I try kicking with open throttle it sounds like it is trying to start but still doesn't. After a few minutes of kicking I will get some backfire and some exhaust. It has a cdi unit which the book states cannot be adjusted for timing. I think the spark plug is firing some other time then at top dead center. I am requesting any and all suggestions. What havent I done or tried. HELP!
     

  2. Anton

    Anton Administrator Staff Member

    Try taking the air filter off and then spray some sort of aerosol (or engine starter) directly into the air intake manifold. If it fires then you may have a fuel problem. Remove and clean the carby. Also drain the fuel tank and refill with fresh fuel.

    You may also want to remove the exhaust and try starting the bike without it. If you have a clogged exhaust the engine will not start.
     
  3. zwebx

    zwebx Member

    cdi, cant they be adjusted or well the timing checked by looking at your flywheel in comparison to your cam gear and usually they will line up (read your manual)


    check the spark plug gap and maybe you have old fuel in there....

    DO THIS FIRST: Set the valve clearances (maybe there too loose/tight to allow any fuel in and or exhaust)
     
  4. Anton

    Anton Administrator Staff Member

    Yep valve clearances are extremely important.
     
  5. darwin

    darwin Well-Known Member

    All those are possibilities but I'd like to know what happens when starting fluid is sprayed into the intake 1st. Easy stuff 1st, bikes that have been sitting 90% of the time its a fuel issue. Hes lucky thats as simple an animal to fix as you can get for a m/c. Been sitting for years he said.
     
  6. Rich S

    Rich S New Member

    So I have double checked all of the suggestions and no dice. I sprayed starting fluid into the intake with nothing resulting. Valves are great and spark plug gap is fine. I haven't tried the exhaust yet and will try that tomorrow. I forgot to mention something earlier. My spark plug lead wire is torn and taped with electrical tape. Would this cause the spark plug to misfire? Thanks again for the help.
     
  7. Anton

    Anton Administrator Staff Member

    You said that you have good spark but check again that the spark plug cable is making contact. Undo the spark plug and hold it against the engine while kicking the engine over and move the dodgy looking connection into different positions to make sure you are getting spark all of the time.
     
  8. BigBlue

    BigBlue Active Member

    Here's a good link on no start for motorcycles: http://www.dansmc.com/troubleshooting2.htm

    Here's a link for testing the CDI: http://www.4strokes.com/tech/testcdi.asp

    I would check all the wiring for good connections. The bike is almost 30 years old. I have two 1980's Yamahas and the wiring just falls apart. One of the wires connecting to the fuse box was just sitting there, causing a no start situation. Get that spark plug wire fixed correctly. I don't know if the bike has a neutral safety circuitry or not. A bad or corroded kick stand safety switch could cause a no start.

    Good Luck,

    Chris
    AKA: BigBlue
     
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