Riding mixed terrain, 1.100-1.600ft, around 68F, 12-50 gearing, NECJ #3 or #2 curently, 175, 42 or 38 currently. S3 extreme head - 26.5cc, fan equipped, checkpoint billet WP standard size. Iridium or regular BR8EG. Also use OEM weight 142gram from 2008 300, RHS.
>When engine cold-er, 2nd gear rips through almost anything. Even 3rd. Bike has traction off idle, controllable pickup torque and responds to throttle almost like electric motor. No matter the jetting.
After 1hr or more riding and some slow heat building section, it becomes a bit sluggish, 1st gear needs more engagement, less throttle elasticity, more prone to stalling.
Engine componentry is pretty much new, maybe 15hrs, but this behaviour is the same regardless of engine state. Whether stock head, high comp, low squish or S3 low comp extreme. As heat builds up, sluggishness occurs. And becoming fatigued during ride and having a more twitchy response rather than traction regardless of throttle further increases fatigue.
Heat rising supposedly promotes rich mixture due to heat expanding molecules, therefore tried 38 pilot and lowering needle, but it seems it does not remedy the situation, but makes it slightly worse down low after that 1+hr of riding and better in the upper rpm.
Once terrain opens up at least slightly, no matter if bike ran sluggish just a moment before...bike goes perfectly. Its only that full bottom up to 1/4 or slightly above range, in which the bike is ridden the most and lack of pulling is felt.
There are no issues with rev out or gunk build up regardless of carb setting. Plug is OK. Coffee to black.
I will further test with 40PJ and #4 needle. Maybe test with hotter and colder plug, a 7 and a 9.
Another thing for consideration - maybe - different oil, as Im using 10w-40, jasoMA2 type which is ok, but made for low performance air cooled 4 strokes, which might indicate low heat performance due to clutch abuse, and clutch does become grabby, increasing heat and need for harder rpm modulation. It could be an additional problem enhancer, not a main culprit. I replace oil every 5hrs. But even new oil after heat up in slow terrain clutch goes grabby, which I believe does indicate low quality for application.
With better oil clutch function remains consistent, but sluggishness does occur. Not yet tried better oil and S3 head combo. Next plant.
Its a 2018 so no map switch.
>When engine cold-er, 2nd gear rips through almost anything. Even 3rd. Bike has traction off idle, controllable pickup torque and responds to throttle almost like electric motor. No matter the jetting.
After 1hr or more riding and some slow heat building section, it becomes a bit sluggish, 1st gear needs more engagement, less throttle elasticity, more prone to stalling.
Engine componentry is pretty much new, maybe 15hrs, but this behaviour is the same regardless of engine state. Whether stock head, high comp, low squish or S3 low comp extreme. As heat builds up, sluggishness occurs. And becoming fatigued during ride and having a more twitchy response rather than traction regardless of throttle further increases fatigue.
Heat rising supposedly promotes rich mixture due to heat expanding molecules, therefore tried 38 pilot and lowering needle, but it seems it does not remedy the situation, but makes it slightly worse down low after that 1+hr of riding and better in the upper rpm.
Once terrain opens up at least slightly, no matter if bike ran sluggish just a moment before...bike goes perfectly. Its only that full bottom up to 1/4 or slightly above range, in which the bike is ridden the most and lack of pulling is felt.
There are no issues with rev out or gunk build up regardless of carb setting. Plug is OK. Coffee to black.
I will further test with 40PJ and #4 needle. Maybe test with hotter and colder plug, a 7 and a 9.
Another thing for consideration - maybe - different oil, as Im using 10w-40, jasoMA2 type which is ok, but made for low performance air cooled 4 strokes, which might indicate low heat performance due to clutch abuse, and clutch does become grabby, increasing heat and need for harder rpm modulation. It could be an additional problem enhancer, not a main culprit. I replace oil every 5hrs. But even new oil after heat up in slow terrain clutch goes grabby, which I believe does indicate low quality for application.
With better oil clutch function remains consistent, but sluggishness does occur. Not yet tried better oil and S3 head combo. Next plant.
Its a 2018 so no map switch.
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