What causes carburetor to break up before full throttle?
Condition: Needle or needle jet is too rich. Carburetor runs clean to approximately ½ throttle but breaks up before ¾ throttle as a result of too rich condition. Correction: replace needle with next leaner diameter and test again.
What do you need to know about jetting a carburetor?
This is the most important step in jetting your carburetor! Remove the main jet. Place needle clip in mid-position. Start engine and run it on the stand. Condition: engine running and main jet out. Needle or needle jet is correct: Carburetor should run clean to approximately ¾ throttle.
What causes a Keihin carburetor to sputter at low rpm?
A lean pilot jet setting will cause your engine to surge at very low RPM’s, bog or cut-out when the throttle is opened quickly and have trouble idling down. A rich pilot setting will result in hard starting, plug fouling at low RPM’s, sputtering as the throttle is cracked opened. The pilot jet isn’t difficult to set.
What causes a motorcycle engine to only run on choke?
Tiny debris particles from dirty fuel can easily block a jet, but the most common cause of clogged jets is stale fuel sitting in the carb when the bike or ATV is inactive. When fuel breaks down, it leaves behind a gummy residue, almost like a varnish that builds up on everything it touches, including the pilot and main jets.
Condition: Needle or needle jet is too rich. Carburetor runs clean to approximately ½ throttle but breaks up before ¾ throttle as a result of too rich condition. Correction: replace needle with next leaner diameter and test again.
A lean pilot jet setting will cause your engine to surge at very low RPM’s, bog or cut-out when the throttle is opened quickly and have trouble idling down. A rich pilot setting will result in hard starting, plug fouling at low RPM’s, sputtering as the throttle is cracked opened. The pilot jet isn’t difficult to set.
This is the most important step in jetting your carburetor! Remove the main jet. Place needle clip in mid-position. Start engine and run it on the stand. Condition: engine running and main jet out. Needle or needle jet is correct: Carburetor should run clean to approximately ¾ throttle.
What are some indications of a lean pilot jet?
What are some indications of a lean pilot jet and/or screw setting? 1 If your air screwis in further than 1 turn, you need a richer pilot. 2 If your fuel screwis out further than 3 turns, you need a richer pilot. 3 Off idle hesitation or bog. 4 Revving the engine in neutral will result in hanging RPM’s, or RPM’s will slowly drop back to idle RPM.