Dyno jet jets are numbered different than a stock style jet. I currently have the dyno jet needle but with factory style jets and run a 162 main. The taper on the dyno jet needle is alot thinner than the stock one and thats why I run the 162 main. Tried the 170 main and 165 but both by reading the plug was a little too rich. I too am experiencing a 1/4 throttle sputter from the needle.
138 main jet is too small. I am running a dynojet and my main is a 142, but is still running lean. I am going to rejet it with gyt-r needles because the dynojet kit is crap. I heard this is the best thing that I can do for the bike. :cry