L to R vibration at Blade

[Joseph Milihram]

When the saw is first turned on the blade runs smooth and straight. But after a minutes or less, a vibration moves the blade left and right doubling the width of cut and shaking just the blade. Have checked for wear none visible. Help?

[scott]

do not use a piece of wood. your saw came with 2 wrenches. unplug your saw. stand in front of the saw (side with switch and adjustments). Raise blade to top. Remove tung (yellow insert). slip open wrench on the shaft then place box wrench on the nut and pull toward you. This would be counter clockwise.