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is there a vacuum

This is a discussion on is there a vacuum within the Technical forums, part of the Caferacer.net Forums category; i have a 79 honda cb400ti and i cant keep it running. there is fresh gas. electrical system is sound. i put my hand over ...

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  1. #1
    Junior Member est1981's Avatar
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    is there a vacuum

    i have a 79 honda cb400ti and i cant keep it running. there is fresh gas. electrical system is sound. i put my hand over one of the two carbs to see if there was suction and when i did this it fired. i put new filters on and it wont fire.

    there is a tube that vents air from the engine head. does this have anything to do with my carb problem?

  2. #2
    Senior Member hahnda's Avatar
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    Have you cleaned your carbs?
    http://www.scramblercycle.com

  3. #3
    Junior Member est1981's Avatar
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    quote:Originally posted by hahnda

    Have you cleaned your carbs?
    yeah the carbs are clean

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  5. #4
    Senior Member nic579's Avatar
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    What you explain sounds like a plugged up dirty carb.

    It sounds like the jets are plugged or I guess your floats could be set horribly wrong or stuck, did you visually inspect the jets to make sure they are clear? I have been surprised in the past by clean looking on the outside jets could be plugged inside. If your tank is rusty the fine rust particles can plug the jets.

  6. #5
    Senior Member hillsy's Avatar
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    When you say you put new filters on, are you talking stock airbox filter or pods? You will probably need to re-jet the carbs if it's pods (covering the carb and the bike firing up is the clue for you)

  7. #6
    Junior Member est1981's Avatar
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    quote:Originally posted by hillsy

    When you say you put new filters on, are you talking stock airbox filter or pods? You will probably need to re-jet the carbs if it's pods (covering the carb and the bike firing up is the clue for you)
    i have switched to pods. re jetting sounds like a plan. thanks

  8. #7
    Senior Member spacmanspif300's Avatar
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    Does choking help? Sounds like a very lean condition.

  9. #8
    Junior Member est1981's Avatar
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    with full choke it fires a couple of times. no choke no fire. i am going to tear into the carb this weekend. school work got be locked down this week

  10. #9
    Junior Member est1981's Avatar
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    with full choke it fires a couple of times. no choke no fire. i am going to tear into the carb this weekend. school work got be locked down this week

  11. #10
    Junior Member est1981's Avatar
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    cant wait to finish it and move on to the next one. want to get it running solid by july.

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