In talking with many people that have tried to transition to raw, much research and personal experience I've found a central theme around why many people don't successfully transition to a raw diet.
Interestingly enough, the reasons for these difficulties are not related to eating fruit, but most often a different reason. They think it's fruit because it's usually the last item they ate.
Many transitioning to a raw diet consume a large amount of fat from nuts and oils to get that feeling of satisfaction. A high fat diet combined with fruit is a recipe for failure and one of the reasons for digestive difficulties.
Eating fruit and not feeling filled up is many times because not enough of the fruit (calorie wise) was eaten. Additionally, once you start eating larger amounts of fruits regularly, you will begin to lose the feelings of hunger shortly after eating them.
I've found that after a few months of eating mainly fruits throughout the day, my cravings and hunger have gone away. When I am hungry, it's subtle and peaceful. The important thing is to eat a good amount of fruit throughout the day, not just one or two servings.
Frederic Patenaude discusses this at length in The Raw Secrets and cleared up some questions about hunger, fats and how to choose the best selection of foods on a daily basis.
All the best for your health!