Won't Stay Running/No Throttle Response.

Discussion in 'Airheads' started by sh1bby69, Oct 5, 2012.

  1. sh1bby69

    sh1bby69 Been here awhile

    Joined:
    Aug 17, 2010
    Oddometer:
    627
    Location:
    Orange County, CA
    So I'm hoping you guys can help me before I just throw in the towel and take it to the dealer. Recently I have took the engine out and sent the frame for powder coating. Also I've taken the cylinder heads off to replace the grommets and seals and what not. I've finally assembled the bike but now that I have a fresh battery my bike won't stay running. It starts only with throttle twisted. But when I try to give it gas nothing happens. Once I let the throttle go it shuts off. Then occasionally it'll I can hear some popping or it'll pop and shut off. I can't figure out what's going on....
    #1
  2. Horsehockey

    Horsehockey A GPS? Huh?

    Joined:
    Nov 17, 2010
    Oddometer:
    369
    Location:
    Vermont
    How sure are you that you have the valves adjusted right?
    #2
  3. ritetwist

    ritetwist Been here awhile

    Joined:
    Jun 29, 2011
    Oddometer:
    204
    Location:
    North AB, CDA
    Any chance you have the cables to the enricher and the throttle butterfly mixed up?
    Shot in the dark, but I have seen it.
    #3
  4. Boxer Metal

    Boxer Metal Mad Scientist

    Joined:
    Nov 3, 2003
    Oddometer:
    3,609
    Location:
    Chico, California
    All of the above and do you have an intake leak?
    #4
  5. Uncle Pollo

    Uncle Pollo Long timer

    Joined:
    Jun 1, 2006
    Oddometer:
    50,551
    Location:
    Albuquerque, Neue Messico
    It's the last thing you touched.


    Drats! ... that is everything!

    Enricheners assembled backwards.
    #5
  6. sh1bby69

    sh1bby69 Been here awhile

    Joined:
    Aug 17, 2010
    Oddometer:
    627
    Location:
    Orange County, CA
    You guys are awesome!!! :clap:clap I adjusted the valves accordingly and not the bike started up smoothly and has throttle response! Thanks!!!
    #6
  7. disston

    disston ShadeTreeExpert

    Joined:
    Mar 22, 2011
    Oddometer:
    12,308
    Location:
    Silver Spring, Md
    Just curious. How did your valves get out of adjustment? Did you adjust them incorrectly earlier? Or was the head off? Just what have you been doing that could cause this?
    #7
  8. sh1bby69

    sh1bby69 Been here awhile

    Joined:
    Aug 17, 2010
    Oddometer:
    627
    Location:
    Orange County, CA
    I had the heads off. Its my first build or rebuild so im learning as i go.
    #8
  9. sh1bby69

    sh1bby69 Been here awhile

    Joined:
    Aug 17, 2010
    Oddometer:
    627
    Location:
    Orange County, CA
    #9
  10. disston

    disston ShadeTreeExpert

    Joined:
    Mar 22, 2011
    Oddometer:
    12,308
    Location:
    Silver Spring, Md
    It's really hard to tell from a video on a small computer just what sounds one is listening to. I think that sounded OK.
    #10
  11. Rucksta

    Rucksta SS Blowhard

    Joined:
    Oct 26, 2008
    Oddometer:
    2,724
    Location:
    Gold Coast
    Sounds about right on the PC as far as I can tell.

    I think I'm hearing PCV valve and the gearbox rattle - both are normal
    One will disappear when you pull in the clutch.
    The other needs an upgrade top a later model reed valve but only if you don't like the turkey gobble noise.

    Have you checked for zero axial float on the rocker arms?
    I could be a bit tappetty.

    Carbs can be swung in a bit at the top.
    This will give you more room for your boots and prevent some of the Bing bite on your shins.
    #11
  12. Rob Farmer

    Rob Farmer Long timer

    Joined:
    Aug 27, 2002
    Oddometer:
    6,731
    Location:
    Loughborough, Leicestershire. England
    I bet you didn't shim the the end float in the rocker arms did you?
    #12
  13. sh1bby69

    sh1bby69 Been here awhile

    Joined:
    Aug 17, 2010
    Oddometer:
    627
    Location:
    Orange County, CA
    I didn't shim the end floats. Is that's what is making the tapping noise or is the tapping noise normal?
    #13
  14. disston

    disston ShadeTreeExpert

    Joined:
    Mar 22, 2011
    Oddometer:
    12,308
    Location:
    Silver Spring, Md
    I found it was the hose clamp screw on my left carb that my foot was hitting. I actually got a sore spot there. Moved the hose clamp screw to the top, instead of bottom, now I don't hit it, or it hit me.
    #14
  15. disston

    disston ShadeTreeExpert

    Joined:
    Mar 22, 2011
    Oddometer:
    12,308
    Location:
    Silver Spring, Md
    Later rockers have shims to eliminate the end float of the rockers. I think you just did a valve lash adjustment? And what needs to be checked and fixed is the up and down movement of the rockers. You don't have shims. You push the rocker end blocks together and hold them while tightening the cylinder nuts on top of the rockers. Sometimes you need to make a tool to hold this together or maybe little brother can hold them together while you torque the nuts.

    This should have been checked when you adjusted the rockers but the way this stuff happens is you have to learn what is happening and we have to tell you stuff in little bits and pieces. Next time you set valve lash you'll check end play automatically.

    The object is 0 end play.
    #15
  16. sh1bby69

    sh1bby69 Been here awhile

    Joined:
    Aug 17, 2010
    Oddometer:
    627
    Location:
    Orange County, CA
    Ok thanks! I think I got the hang of it. Basically loosen the bolts again so that I can have zero VERTICLE play on the rockers then shim the valves correct?

    Thanks for helping out a noob!
    #16
  17. disston

    disston ShadeTreeExpert

    Joined:
    Mar 22, 2011
    Oddometer:
    12,308
    Location:
    Silver Spring, Md
    We are talking about the end play of the rockers. Later rockers have shims. Your rockers need to have the end blocks pushed together. Sometimes you will have to make a large clamp tool with sockets on the ends to push the blocks together. But usually you can do the pushing with your hands. You can also push the blocks together by partially loosening the nuts and whacking the blocks with a rubber mallet. Or putting a socket over the block and hitting it with a regular hammer, but not too hard, a couple of small whacks is better than big whacks.

    What ever method is used eliminate the end play.
    #17