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New Style Carbs on an Older Model Powerhead

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  • New Style Carbs on an Older Model Powerhead

    I have a set of three carbs off of a 1998 C90TLRW, and was wondering the difficulty in putting them on an older 1991 E90TLD. The carbs bolt up great, just the middle carb from the 98 has the primestart and fuel enrichment valve on it. The 91 power head does not have the two vacuum lines for the system. Is it possible to cap off the two lines from the middle carb and use the setup normally? Basically I am using newer parts on an older motor. I can retrofit the newer electronics, just won't have the vacuum attachments the special middle carb has. I have a separate thread discussing the electronics if interested.

  • #2
    prime start will not work and you have no choke,
    so will be hard to impossible to start a cold motor
    no way to get extra fuel to the cold motor


    • #3
      If I have to, I can use the 98 intake on the 91 powerhead. It gives me the nipple to drop in fuel behind the carbs. My only dilemma then is to find a vacuum to pull on the diaphram on the enrichment valve. Any ideas where I can pull a vacuum from?


      • #4
        it is not a vacuum, it should be a pulse from the crankcase.
        just like the pulse to operate the motors fuel pump.
        I have no idea which crankcase it normally is tied to