Bored carb = high idle?

tor*p*do

tor*p*do

Squarenose FTW
Site Supporter
Location
NW NC
Put a ported 701 with a bored carb in my ski this winter.
Runs great with jetting from the builder,
but it seems to idle high
Is this typical with hi performance motors and/or bored carb?
I noticed there is more open space around the butterfly than on the oem carb . . .
 
Big Kahuna

Big Kahuna

Administrator
Location
Tuscaloosa, AL
If there is open space around the butterfly then you will be passing air which will act just like you are adding more throttle. The air acts as a suction and will suck more fuel out causing the higher idle. I would replace the butterfly plate with one that fits.
 
tor*p*do

tor*p*do

Squarenose FTW
Site Supporter
Location
NW NC
Big Kahuna said:
If there is open space around the butterfly then you will be passing air which will act just like you are adding more throttle. The air acts as a suction and will suck more fuel out causing the higher idle. I would replace the butterfly plate with one that fits.
Click to expand...

good idea, except butterfly is stock size and replacement
does not look like it will not resolve the daylight around it.
Any other ideas?
 
#ZERO

#ZERO

Beach Bum
Location
Florida - U.S.A.
Someone may have bored the carb with excessive clearance or the throttle plate is worn out. Hold it up to a light with the idle screw removed and the throttle plate completely closed and see where the light is shining through.
 
R

restosud

or the bore is worn out where the plate hits it,or the plate is worn from vibration where it meets the shaft at the bore,or,or,or!
 
tor*p*do

tor*p*do

Squarenose FTW
Site Supporter
Location
NW NC
got to messing with the throttle cable
and realized it was hanging inside and frayed
replaced cable with a spare and problem is GONE!!!! :arms: :arms:

:veryhappy: Memorial Day Weekend! :woot:
 
You must log in or register to reply here.
Top Bottom