Hate to tell you this, but even Harleys make more hp than your bike does. I think your bike makes horsepower somewhere in the mid 50s' Sure, your bike has lots of low end grunt, but high rpm power is lacking. When it comes to making horsepower, the problem is there's always a trade off. Always. If you can find camshafts that are ground for making more high rpm power, you're going to lose low rpm power and probably gas mileage. Try to get a few extra ponies with a less restrictive air filter and exhaust and you have lots more noise. Put on a larger diameter carb and you gain a few high rpm hp but lose low rpm power.
The best way to get a few extra hp but keep the engine's present power delivery characteristics is to increase the displacement. Like the old timers say, there ain't no replacement for displacement. I don't know if the cylinders can be bored out to accept the 1600's pistons assuming they got the extra displacement with a wider bore. If it was by stroking the engine, then swapping cranks could be an impossibility. I do know that while the engines look a lot alike, there are some major differences between the two. For now, you might check for after market big bore pistons.
