we.tl/t-Aq3prKKt9MMrxq41

Starts on first kick, idles, but constant blubbering in the 1/4 to 3/4 throttle range.  Full throttle takes off like a scalded cat!  Needle clip in top groove, new needle-setter with good O-ring, and 130 main jet.  Pure smooth power kicks in at around 4,000 rpm.  First part of vid is gentle mid-throttle acceleration through the gears; last part is full throttle.  (2 minute vid)
Could sure use a little guidance from the EnduroWizards!  Cheers, Pat
 

One possible cause for those symptoms is wear in the needle and needle jet .
OEM part numbers are needle  438-14116-08  ( 5EJ8 )
                                needle jet   445-14141-38  ( 241  O-8 )
A thorough ultrasonic clean of the carb would be a good starting point , before actually replacing hardware .

+1 on Swoop56 comment regarding the needle and needle jet. Replacing those items on my DT400B and DT250B absolutely eliminated the blubbering. Unfortunately I cannot find anyone selling the needle jet 445-14141-38 for the DT360A. So on my DT360A I only replaced the needle. MarkT shared info on a more common alternative 159 needle jet that I plan to try this year.

I'm with Swoop56. Worn needle jet. Alternatively havev you got you idle mixture screw fully in!! Instead of 1.5+ out. Is there something blocking the air feed to the needle jet--have a look. Had the slide guide pin gone walking & slide has turned. Oring should be good or would never clear on full song. Back to Swoops thought though. Worn needle jet, the metering bit at the top.

stock 241 jet, VM30SS 


159, Q-6


159, Q-6


L=159 Q-6, R=241


159 jet from a VM30-83 in a VM30SS w/the 6 series needle from the 30-83. Ran a lot like a VM30-83 in this configuration.


241 in a VM30SS

Gotta be careful that the tall top jet has the right slide for clearance when throttle is closed. Just saying.