Tao tao 110 quad

[woodywood57]

I have a 110 quad I am bringing back to life. While checking the timing spining the engine over by hand, spark plug out, there is a tight spot in the engine. To me that means a crank/main bearing problem. Anyone else ever had that issue? It should spin freely with the plug out?

[darren]

if timing is good ,stator is not broken or piston not scored what's compression like ?

[Thumper]

The valve springs still can cause resistance to rotation. If it is smooth resistance, could just be that. Should be zero resistance approaching TDC on the firing stroke. Since valves should be fully closed. Grinding or grating, or chunky...bad.