Altivillan, it would turnabout the same on the stock BME muffler, had the tune length on that dayway off. I should be able to hit about about 7200 now with my current set up (piped), that is if a xoar is a little more load than an nx23x8 or menz-s 23x8, if lighter loading I should hit 7400. Guy, which loads more a xoar or nx?? I keep forgetting.</p>

Closetguy,,,With the current carb you should be able to make it 4 cycle with the high needle, if not there is probably something wrong with the carb. You are really cranking if you get 7500 on a vess23a and a stock muffler, do you have a reliable tach??</p>

That muffler might be too restrictive for the 58, letit breath.These motors are happiest spinning around 7, and mine really likes 7600+ with a vess23a</p>