Fork oil weight and level for Z1r

I put in new fork seals and 10w fork oil in my Z1R.Front end seams to bottom out over big bumps.Does any know the oil level and if I change to heaver weight oil 30w? how many CC after removing oil from forks.

The level should be 17.4" from the top with the fork fully extended and the spring removed. (book calls for 10w oil) If it still bottoms (mine doesn't) you can raise the level by small (.5" at a time) amounts. Don't get the oil level too high or the forks will lose some of they're travel (and blow fork seals) when they hyd. lock without enough air space.

i like 30w synthetic motor oil 180-188cc with bone dry forks

Per FSM:

1978 KZ1000-D1 "Z1R" fork oil level using SAE10W20 should be 16.5" or 420 mm from top, fork fully extended, with spring left inside (i.e., spring not removed).

1979 KZ1000-D2 "Z1R-II", fork oil level using SAE10W20 should be 17.4" or 441mm, fork fully extended, with spring removed.

Putting 180-188cc into a dry fork, or 160cc into a wet fork, supposedly results in these levels.

An appropriately marked wood dowel makes a handy dip-stick.

Good Luck!