Problem with my bike
I am having an issue with my 2023 KTM 250 SX-F engine during reassembly and I am looking for advice on what may be causing it.
When I removed the cylinder, I tested crankshaft rotation by turning the flywheel bolt by hand. The engine would rotate a few full turns smoothly, but then it would suddenly stop and no longer continue rotating in that direction. If I rotated it the opposite direction, it would again rotate a few turns before stopping.
After reassembling the engine, the same issue continued.
The bike was in neutral while testing, and the clutch assembly was installed. The crank was rotated only by hand using the flywheel side bolt. The stopping feels like a hard mechanical stop rather than normal compression resistance.
Because the issue was present even with the cylinder removed, I do not believe it is related to cam timing, valves, or piston rings. I am wondering if this could be related to the crankshaft, transmission, clutch assembly, starter gear train, or another lower-end component.