anyway my question was the prindle's tiller has next to no weight on it when sailing unlike my 18,seems I am always fighting the tiller.Measured the rudders and they are parallel, are all 18's like this?
No. You need to get your helm balanced. It is not just an issue of rudder parrallelism. The first thing you need to do is make sure you're sailing with your rudders fully locked down. If you are and you still have excessive weather helm, then you need to adjust your rudder rake.
If you have the new rudder castings, this is simply a matter of loosening the cam plate adjusting screw, moving the bottom tip of the rudder forward, and re-setting the cam plate. If you have the old style rudder system, you will need to fill the hole in the rudder blade with epoxy and re-drill so the bottom tip of the blade is farther forward.
There have been ton's of discussions about this on the forum as well as recenet Hotline articles on the subject. Point is, you can definitely correct your rudders to get your helm dialed in.