if the previous owner installd a 42 pilot jet the choke being removed will not be a problem to start it,just pump the throttle a few times before starting and you should be good,but you might have to hold the throttle easy for a min. or two untill it gets a little warmed up.The removal of the choke DOES slightly increase the airflow through the carb.Judging by the mods the previous owner installed it should be jetted correctly,pull your plug and check the color,it should be light tan to grey.hope this helps.
If the plug is not tan goto the tech article section on this site and look at the spark plug color chart to see what is causing the color(ie.:lean or rich)
sold and missed:00' 401ex
bored .20 w/ honda piston,HMF full system,hotcam stage2,sparks degree key,165 main,42 pilot,chokeless,twin air or UNI,moose case saver,renthal CR bend bars(red),AC chasis skid,AC bumper,AC nerfs,14t front sprocket,n-style seat cover,pro design kill,easy pull clutch,park brake block off,baja ring rims on the back,2+3 offset ITP t-9's on the front with holeshot xcr's all around,race cut front plastic, OMF scoops and PRM swinger skid
94 toyota pickup-3" lift 33" cooper tires and a cold air intake
I will be back on a 400 shortly!!