Top end assembly

[Z50Tim]

Ive done a short video of the noise. going to take it back apart this evening.

https://www.youtube.com/watch?v=iejY...e_gdata_player

[swiss18]

sounds like piston hitting the valves mate, take it apart and have a look, u will definatly see if that is the problem, is it a new piston u have put in or the old one, u definatly got the timing marks lined up on the cam chain sprocket and the flywheel? that sounds horrible mate i would definatly double check its the right piston for the engine, it not likely but possible that the head gasket ring is slightly over hanging the bore and the piston clapping that, i would have thought if it was the valves that it would bend/brake them and stop running.

[Z50Tim]

Its the original piston from the xsport engine. The bottom end is a zongshen 90 from way back. Ive used the xsport 110 barrel and piston and the e22 head of the 90. Maybe i should have used the xsport head. ill have a good look tomorrow.

[Z50Tim]

Cracked it. changed the head for the original xsport one. starter second kick. no knocking or anything. i couldn't see what was causing the knocking.