Celeste wrote on 04/24/23 at 09:24:20:Unable to respond due to website rules. (10 post minimum)
Let’s go thru the works.
-Mikuni VM (round slide) 36mm Carb.
-Stock Air Filter
-Straight Pipe with open baffle end
-190 Main Jet
-Needle at 2nd from the top
17.5, 20, 22.5 pilot jets do not start idle at any nor successful sequencing combustion.
On choke, all produce backfire with blue flames.
Adjusting idle screw can produce lower bangs leaning out ( screwing out clockwise) or wet bangs when enrichment (screwing in counter clock wise) at 20 Pilot
On open idle, 0 throttle, pops occur. Sometimes a rare thud
No engine modifications
No TCI modification.
Spark presents blue, gapped at .35 inch
Is this a new carb and new problem?
Have you checked compression?
Is valve lash clearance within specs?
Make sure the carb is snug and tight in the intake manifold and the clamp is working. The tiniest air leak there will cause running, idling, and tuning problems.
I’m using a 27.5 pilot jet at 2.25 turns out on my VM36. Stock air box and minimally baffled open turnout exhaust. Easy starting, steady idle.