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DRZ FCR-MX pilot circuit - needle diameter

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1)year/make/model: DRZ-SM K8

2)conditions (elevation,temp,humidity if extreme,type of riding: effectively sea-level (~1000ft); summer temps up to 115 (currently 95F); all round commuting/fun - trail riding

3)modifications (pipe,air box,motor): Pro-Circuit T4 open system; TT FCR-MX; 3x3; stock oiled air filter

4)current jetting:






Merge extended fuel screw

5)running issue that is trying to be cured

a) Surging (not quite sure about the terminology - I believe its running rich) at constant throttle - 1/8 to 3/8.

🤣 Fuel screw not responding as expected.

History- I installed the carb last winter (40-60F) and the bike was awesome.

As last summer approached the surging appeared and by mid summer (above 100F) the bike was running like shit at any constant RPM below 1/2 throttle. The bike would also idle with the fuel screw at 0 turns! I changed to EMR-3 and 42PJ and it was much better - though I was never completely satisfied. The bike still idled with the FS at 0.o1 turns!. I changed back to EMN-3/45pj for the winter but now with spring (90 and rising) the surging is beginning to reappear.!!

In fact, I could not 'kill' the bike with the fuel screw all the way in even with the 42PJ in mid winter..!

I took the courage to start this thread after spotting this from Eddie in the DRZ forum (recent Leak jet thread):

your issue currently is the EMR has to lean of a straight diameter work with out the pilot air jet.

Don't know if i'm mixing things up but, what should I do?

w/EMR Should I replace the PAJ (doesn't this make the idle circuit leaner?). What pj would I then need, 40?

Whats wrong with my pilot circuit?👍

Carb has been cleaned several times, valves are in spec,

Thanks in advance,

I hope to get this sorted!

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turn idle speed down as low as the motor will stay running when hot and redo the fuel screw test.

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Will try again as soon as I get the chance as its been a while. When I last did it, fully warm bike - 60F weather, I got peak idle as described in the sticky at 1/2 turn w/ the 42pj. This didn't make any sense based on what i've been reading on the forums. Hardly anyone uses a 42 PJ, let alone it still be rich .?

I have been using the 45 at 1turn in fear on being lean

brand new (now 15 months old) FCR-MX from TTstore

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