[ltz666]

I gotta z400 with+4 stroker crank and vertex 94mm piston, after I put it back together I was trying to start it and when it did start it was knocking pretty bad,it was only running for about 20 or 30 seconds,so I took the head off and the ex valves where hitting the piston,is it from the cams being retarded a tooth?Cause I used clay on the piston before I ran it and at that point it was in time I didn't torque the head I just snugged it though, adjusted the valves and turned it over by hand took back apart and checked it out and there was still room to adjust the valves,and nothing was hitting at this point,if anyone can help I appreciate it, Kevin

 

[jetmech25]

If they hit with that setup, it must have been off. Make sure you line up the line next to the “T” centered in the window (not the actual T) and remove all slack from the exhaust cam side before installing the cam. Also, make sure both guides are installed correctly.

 

[ltz666]

it was ok when I first put it in time,but I guess there was more slack then I though I'm just going to buy new ex valves and try it again