idling requires fuel delivery from the low speed side of the carb did you try adjusting the LS needle

are you using a pressure tank or a converted to fuel pump set up ??

cleaning the complete low speed fuel route involves pullling the top dime size cap and cleaning the low speed drip chamber did you do that ?

is this a new /recent issue with the motor ? how is compression ?

Check the compression. If it is low, it will run faster, but won’t idle worth squat.

well what are the compression numbers ??? if electricals are OK we can assume it is not sucking fuel properly to feed the cylinders

check all negative pressure points…

a- starting at the fuel pick-up (change tank and hose if neeed be )

b – divide to conquer…. feed the carb manually with a small fuel supply and hose to the carb inlet thus bypassing the, air pressure pulse , hoses and pressure tank as a problem source

if idling is ok work backwards . low pressure pulse feeding the tank (bad check valves behind the inlet manifold)

c- if still idling bad with a small fuel supply on the carb inlet …….. problem is on the engine side

d- possible loss of crankcase negative pressure causing a weak pull on the carb idle circuit fuel supply ( crankshaft bearings allowing external to be sucked in the crank case instead of fuel from the carb)

e– carb gasket not sealing , LS needle packing inadequate sealing,

f- check the throttle plate at the rear of the cab .. it should be pretty well closed at idle to have the fuel sucked out of the idle chamber

g- btw did you clean out the VERY small jet in the side fuel channel feeding the upper half of the carb ? (look closely inside the feeder
channel) clean it out with a VERY VERY small wire and flush with carb cleaner and air pressure blast

• This reply was modified 3 years, 3 months ago by crosbyman.
• This reply was modified 3 years, 3 months ago by crosbyman.

or could it be flooding at idle ?