Heavy Breather 50mm adapter

Discussion in 'Touring Models' started by cdnmike28, Sep 5, 2010.

  1. cdnmike28

    cdnmike28 New Member

    I installed a heavy breather on my 09 Street Glide. At the time of installation I was not sure what size of throttle body I had so i did not install the 50mm plastic adapter piece. The bike has been running fine. Now knowing that I should have installed this adapter, I was wondering what purpose it really serves (since all seems well). What negative effeects can be caused be not installing the adapter?
  2. oiler

    oiler Active Member

    When I installed my Heavy Breather I asked myself the same question. I installed the 50 mm adapter only because the instructions say so. I know that once the 50 mm adapter is installed in the backing plate, the adapter fits nice and snug into the intake tube. The only thing I can see is that the hole will be 50 mm instead of 58 mm when installed. I would call a few dealers and talk to the techs before taking it all apart. Let me know how you make out.
  3. Dr. Dolittle

    Dr. Dolittle Experienced Member Contributor Retired Moderators

    If the instructions said to install the adapter for your specific bike, I would take the short amount of time to take everything off and install the adapter. Otherwise, you'll have that in the back of your mind every time you hear a strange noise or your bike hiccups even slightly.

    But that's just me!
  4. cdnmike28

    cdnmike28 New Member

    I am going to take it apart and install the adapter-I had to order another one because of course I lost the one that came with the kit. I figure HD wouldn't have put it in the kit if it wasn't needed, so I might as well do it right. If for some reason it makes the bike run better I will be real happy because like I said earlier, I think the bike has been running great all summer. Thanks for the reply's guys!
  5. HKSkully

    HKSkully Member

    Friend had one installed when it shouldn't have been and it dislodged and was sucked into the throttle plate, jamming it in WOT. Since it is a fly by wire bike, there wasn't any means to manually close the throttle. Quick thinking was in order to shut it down at the kill switch.

    I could just imagine if this happened in traffic.
  6. x1rider

    x1rider Member

    The stock TB is 50mm so you do need the adapter.
    When I switched to the SE 58mm throttle body on my StreetGlide, I took the adapter off because of the bigger throat diameter.