Recently did a topend for this motor. Cylinders were egg-shaped, one is .002 over and other is .004 over. Ring end gap was in spec, everything went back together smoothly. 1st compression test without running was only 90psi each. Seems low to me but my machine shop I used said it will go up once the rings seat.
I've done about 5 2 stroke rebuilds and none have been this low out of the gate. Is this normal?
Also i notice the timing linkage seems to jump around when I pull it over and the yamaha manual says to adjust the diaphragm assembly. I attached the part diagram. Is that assembly just to keep pressure on the linkage so it doesn't do what's happening to mine?
I've done about 5 2 stroke rebuilds and none have been this low out of the gate. Is this normal?
Also i notice the timing linkage seems to jump around when I pull it over and the yamaha manual says to adjust the diaphragm assembly. I attached the part diagram. Is that assembly just to keep pressure on the linkage so it doesn't do what's happening to mine?
