2011 300 JD jetting kit thoughts.
 

Hey guys, I have the standard 36mm carby on the 2011 ec300 and I have just thrown in the standard JD jetting kit with the blue needle 3rd clip, 170 main and 38 pilot. It literally has a new piston and rings in it and would just be run in.

It it really torquey down low, but up top it seems to be a little stop/start like its surging so to speak..here is a pic of the plug.
Anyone have any success with the JD setup? The current temp here would be about 30degrees's and at sea level ?

I guess i don't want to run too lean. The previous owner had a JD blue needle with a 178 main and 42 pilot but it wasn't running too clean.

Any thoughts on this black art of jetting?

First thing to do- Drop the needle one clip (raise the clip one notch). That will help determine if it's the needle making the issues up top. If it cleans up, which it may, then you are sorted. If not, come back with a report and we can help with the next step.

thanks for the advice mate, when it cools down here ( apparently going to 42 degree's here tomorrow ) i'll drop the needle and see if it was running rich.