Thanks in advance for your help!!!

1. I recently started riding at 7500-10000 ft. With an FMF Powercore exhaust, what's a good starting point for the main jet? I believe that there's a 190 jet in it, it was rode at 2200 ft, which from my minuscule knowledge of motors and carbs, seems like a large jet, even at that altitude.

2. I was about 15 minutes into riding and I lost power from approx 1/2 to full throttle. The plugs fouled out (brown residue, not wet), and in the process, they were dropped and gaps closed. Which leads me to my next question.

3. What is the factory recommended gap, or the correct gap? Has any one used a ignition system tester like this --> http://winnerscirclemotorsports.net/pdf/15-Tools.pdf Page 6 Part No. 08-0122

Please explain... Thank you again.

 

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Lot's of info. Spark plug gap should be .026" and a good start for the jetting should be around a 155 main for that high of elevation. You are way too rich for a stock carb at that elevation. Try that and let us know how it goes.