The pilot circuit.

[the_Journeyman]

Ok, so, I've got a pilot circuit issue it seems.  1999 Monster 750, OEM airbox, BCM filter, Termignoni Mufflers.  Engine is 100% stock, and I've just replaced the badly work emulsification tubes.  I know something is up in the pilot circuit, but not sure if it is rich or lean.

Facts

1)  Starts with choke what I would consider normal.  A throttle blip is necessary, but it starts quickly

2)  Once warm (after riding around neighborhood for a few minutes) there is terrible response just off idle.  Seems to be fine mid-high RPMs

3)  If idling, I can blip the throttle and it kills the motor.

4) If I baby the throttle, it'll come up, but is very difficult to do so without killing it.  Once engine speed is up, it's fine

5)  If I barely open the choke, off-idle response is improved, but mid-high suffers

6)  On deceleration, a lack of engine braking is noticed

7)  I don't seem to have any vacuum leaks, I found & fixed the one I had causing problems with it throttling up.

Should I start with the idle mix screws?

Should I be prepared to change the pilot jet?

Are these rich or lean symptoms?

Thanks folks!

JM

[ducpainter]

Assuming you set the floats correctly just open the screws to 3 1/2 or 4 turns

[the_Journeyman]

I'll see what happens!  I found the nicely labeled pic of the carbs by Greenmonster in another thread.  That pic will be very useful!

JM

[pslinux]

Can you confirm the results of this? I'm having the same issues described.

[koko64]

 

[alibaba]

I have found on all carburated bikes these symptoms 90% of the time are caused by a clogged pilot jet system.  And 90% of the time owners who swear they have cleaned the pilot jet system (gas and air) have not really gotten it clean.  After a thorough cleaning of all parts of the system, I like to squirt some WD40 in the air inlet in the mouth of the carb and look for the sprays coming up from the floor of the carb to 'indicate' that the system is unobstructed.