Originally Posted by Load Clear
So, will this enzyme additive work its way out after a couple tanks or do I need to drain the fuel? I added it to one tank. I've refueled only once so far but did not add any more startron.
I don't know for sure if your additive is at fault, but I do know that the need to use the cold start enrichment longer indicates a lean issue with the pilot circuit. I would replace the float needle if the tip is found to have a witness line, set the float height with the help of a float height setting tool to 14.7mm, replace the pilot jet and set the idle mixture via the following method:
Start the engine and warm it up. Set the idle CO to 3-4%. Set the idle speed to 1500 rpm. If you don't have a way to measure CO%, lower the idle speed below the factory spec. Starting from a setting that is known to be lean (1-1/2 turns is likely but not guaranteed to be), adjust the fuel screw to obtain the highest idle speed. Adjust to 1/8 - 1/4 turn richer than that. Then, adjust the idle speed back to 1500 rpm.
It is still not running well in first gear or on start up.
For diagnostic purposes, the gear is mostly irrelevant. Throttle position is the important thing:
Put some tape on the throttle housing and the edge of the grip. Mark zero throttle with a sharpie. This is best done with the engine idling, so you can tell when the slack in the cable has just been taken up. Turn off the engine and mark wide open. Now take a tape measure (metric works best in my opinion) and measure the length of the arc. Put a mark at the mid point. Duplicate this procedure to mark the mid-point between here and zero throttle opening to get 1/4 open. Repeat for 1/8 and 1/16 openings. With the help of the marks, determine precisely during what throttle opening(s) it misbehaves. Don't have an accident trying to look at the marks while riding. If you do, I'm not responsible!