03-04-17, 10:34 AM
Since Yamaha chose this bonkers method of using a long rod pushing through the entire engine to disengage the clutch it is bound to happen. The body of the engine is aluminium which has a large thermal expansion compared to the steel of the pushrod, so effectively the rod becomes shorter.
You should be able to arrange the bottom adjuster on the clutch to give you enough range on the one at the handlebar to compensate while riding. Did you try it?
The cooling system concentrates on the cylinder head, if you’re crawling along slipping the clutch for long periods the bottom end will get much hotter than usual. It is very dependent on a decent flow of air to keep the bottom cool, if all it gets is what convects off a blazing hot exhaust collector it’s going to suffer.
That said, it’s worth checking the cooling system. if the fluid level has dropped, a hot engine won’t turn on the fan because the sensor is high and dry on the thermostat housing.