MOTORCYCLE THROTTLE BODIES

[sdelanty at sonic.net]

>> enthusiasts who can enlighten me on the subject of motorcycle injection
>> throttle bodies?
>> 1, Are they generally individual with individual spindles linked together
>> externally?
>> 2, Are the injectors fitted into the body or into the head/manifold?
>> 3, What style of injector do they use; o-ringed Bosch type?
>> 4, What size are they generally: 40mm or so?
>> 5, Do they have individual air-bypass adjustment screw or the like?
<snip>
>> Thanks for help
>> Rich.

>All i can do is give you the specs on a set of manifolds i have here. I
>think they are of a kawasaki GPZ900 but don't hold me to it.
>1. Individual with external screw and spring type links. Ie all shafts
>in a line and the end of one drive the start of the next with the
>throttle cable in the middle.
>2. Injectors in the body. The bodies are made by mikuni.
>3. Injectors are the same as D jet or L jet bosch ie a rubber hose to
>fuel rail and 2 orings seal to body. They are low imedance injectors.
>4. 34mm
>5. No idle air screw. There is a fast idle cam that opens all the
>throttle's a little
>Hope this helps
>David Chambers

   I can add a small amount to Dave's reply.
  I have a genuine '81-'83 KZ1000-KZ1100 service manual here in my lap...

  1. Yes, what Dave said..
  2. the KZ1100 injectors are in a short manifold casting that bolts
     to the head. These castings are connected to the throttle bodies
     with a short, fat, rubber hose.
  3. Yep, bosch injectors with the rubber hose.
  4. Doesn't give a size, but the KZ1000 carbs are 34mm, so they're probably
     at least that big.
  5. The KZ1100 setup has idle balance screws.

  Other tidbits from the manual:
   The KZ1100 fuel pressure is 33psi at idle.
   There are 2 different air metering setups. One uses the "flap in the
   airbox" to meter air, along with a switch on the throttle that
   senses fully closed and WOT. Also an air temp sensor in the airbox and
   an engine temp sender.

   The other setup uses only a pot on the throttle shaft, plus the airtemp
   sensor and the engine temp sender.

   Both systems use a non adjustable pressure regulator connected to
   manifold vacuum...

   Engine output is rated at 108HP @ 8500RPM.

                Steve Delanty  <sdelanty at sonic.net>