I have a 1998 Yamaha warrior, I've had it since last summer
And I have gotten bored with the power, I ride a lot of open feilds
, some trails, hills and technical stuff, and I was wondering which
Quad would be a good step up from the warrior

 

If you like Yamaha how about a Raptor 700R?

 

I would, but that's a pretty penny to get the big boy

 

Any honda is a step up froma yamaha...

IDK... just look on c-list, find something you like, go test ride it...
Recommendations: 300ex, 400ex, kfx 400, z400, raptor 660, dvx 400 (artic cat?)...
Some other stuff... banshee 350, 250r, yfz 450, 450r, ltr 450, kfx 450, 700xx, predator, kfx 700... the list is endless..

 

I've heard a lot about the raptors and if ur riding open fields it would seem to be that the raptor would be a pretty good choice and plus they have plenty of torque for fun