Backfire, capow!

Discussion in 'Technical' started by justin has a 74, Aug 30, 2010.

  1. Mavman72

    Mavman72 Gone backwards but lookin' forward

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    You seated the mixture screws and the car ran better...You have a vacuum leak or a popped power valve or the secondaries are stuck partially open.(are you useing thin gaskets or thick ones at the carb base/spacer???) I recommend useing the thin ones.The thick ones make it easey to warp your carb base plate if your not careful... Just plug the PCV fitting till you get the thing ironed out, or replace the leaking PCV hose and go from there before taking the carb apart.Good luck!!!
     
  2. justin has a 74

    justin has a 74 Maverick bandit official

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    I just replaced the powervalve:D
     
  3. justin has a 74

    justin has a 74 Maverick bandit official

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    yep yep yep, ill keep you guys updated:drive:

    Got a standard gasket lol
     
  4. justin has a 74

    justin has a 74 Maverick bandit official

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    Grabbing a vacumm guage today and i couldnt sleep last night. Shims might help on the rockers if the valve isnt seating over 2 grand?
     
  5. justin has a 74

    justin has a 74 Maverick bandit official

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    15 on the gauge and it bounces, go to rev it and it goes back to zero and then to normal range (20) then back to 15.

    Says late timing, but ive been messing with the dissy with no luck......


    capow!
     
  6. justin has a 74

    justin has a 74 Maverick bandit official

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    Spark plug gap is at 54 if it means anything.
     
  7. dkstuck

    dkstuck Member

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    Get your gap down to 32-35 tops,,,, triple check your firing order,, do it just to amuse me,,, check your cap for cracks and may have to wait till dark, but check your coil for arcing.

    Did you check your power valve? If you take it out and suck on it you will tell if it ruptured. Also, are you using the correct gasket for the power valve?

    ,,, I'm tired,,, will check on you later,,, maybe you oughta make that drive here!
     
  8. maverick75

    maverick75 Gotta Love Mavs!

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    If it bounces around its usually an ignition miss or a sticky valve. Why is it set so big? If you dont have MSD put it back to the recommended specs. Which on a duraspark is .044 or with points its .034 .
     
  9. justin has a 74

    justin has a 74 Maverick bandit official

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    I read for factory specs on an 87 302 its 54, thought it was a little big too.

    Ill put it in the 40s and see what happens, also ill do everything mentioned. I hvae replace the powervalve.
     
  10. maverick75

    maverick75 Gotta Love Mavs!

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    Those specs are for the 87 ignition system that you are not running.
     
  11. Mavman72

    Mavman72 Gone backwards but lookin' forward

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    So... Was the PV bad???
     
  12. justin has a 74

    justin has a 74 Maverick bandit official

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    Dont think so. I havent changed it in 2 years and ive had alot of backfires.



    Car was still backfiring after everything. Cleaned the plugs and regapped them. Maverick maaniac and I were talking to a motor guru and he said throw that carb spacer in the trash and give it a try. Ill let you guys know around 2 pm.
     
  13. justin has a 74

    justin has a 74 Maverick bandit official

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    Well, without the spacer it runs alot better. Still spitting but revs to 3 grand.
     
  14. justin has a 74

    justin has a 74 Maverick bandit official

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    Ok ok ok, maverick maniac is going to let me try his new holley collecting dust in his garage. I think my holley crapped itself since the secondarys were still pouring gas with the car off not to mention when it was idling also.
     
  15. maverick75

    maverick75 Gotta Love Mavs!

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    Where was it pouring gas from? Be specific.
     

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