Intake Question

Discussion in 'Softail Models' started by cory.moor, Jun 29, 2011.

  1. cory.moor

    cory.moor New Member

    I have a 1990 FXSTS that I just put a new motor in. The intake has a threaded hole on the top that my old one did not have. The motor runs beautiful when the hole is plugged but I am having trouble finding out the thread size for a plug. The only thing I haven't tried is pipe thread, does that sound right to anyone?
  2. Breeze3at

    Breeze3at Well-Known Member

    I think that's the vacuum port for the VOES that came on later years. I think it is a pipe thread, try one carefully.
  3. Slo-Ryd

    Slo-Ryd Junior Member Contributor

    You made no mention of what year the motor is. If it's a newer year motor 99+ more than likely it's the fitting for the MAP sensor. Although I'm not sure if it's truly threaded. The map sensor has a ribbed rubber seal that gets inserted into the manifold and the sensor is held in with a torx head screw which should be the smaller hole adjacent to the port. That hole isn't tapped through, so you should have no problem with having to plug that one.

    If it is indeed a newer manifold, you have two choices, use your older manifold if you still have it or figure out a way to plug this one since you don't need it on a 1990. A new map sensor is around $35 if you didn't want to fuss with trying to figure out how to plug it. Stick in what should be there and forget about it. I would opt for the correct intake though, jmo.
  4. cory.moor

    cory.moor New Member

    Thank you both for the information and advice. I will try to get it done one way or the other before my ride this weekend. Again thanks, and have a great 4th of July!