Whoa, throttle back there Tommy: there are many ways to increase horsepower, from the relatively simple to full race-engine rebuild with Falicon crank, Carrillo rods, race valve job, and high-compression pistons.
You “threw” a Dyno jet kit on your old bike(s)? Jet kits can be a hairy bitch to tune properly. The situation involves multiple variables: altering fuel flow’s one thing, intake and exhaust another. Tuning all together usually takes awhile with trial-and-error. Hope you had a dyno handy and did a plug-chop. Half-ass jet kit jobs are far worse than nothing at all.
Pipes, air filters, and jet kits may (or may not) be of questionable value on recent street motorcycles, from a performance standpoint. Granted, most stock pipes weigh a ton and sound awful. Also, in the U.S. many bikes arrive deliberately lean to pass EPA restrictions. Many tuning shops worth a shit (there are several, including Mr. Kyle’s shop) offer “performance packages,” which may include: 1) pipe 2) jet kit 3) air filter 4) dyno tune 5) slotted cam sprockets 6) intake alignment.
EFI significantly eases the pain of tuning. Some of the aftermarket units out now (e.g, Power Commander III) allow tuning of all sorts of engine variables. A tuner can gamble a little and use pre-existing maps, or have the bike dyno’d, profiled, and tuned based on the specifics of that particular motor. A Triumph dealer in the Puget Sound area offers such a package for a nominal sum, e.g.: my buddy just picked up his new Triumph Tiger after their “performance tune” and notes greater horsepower (package includes before-and-after dyno printouts) plus a smoother powerband.
There are all kinds of ways to skin a cat, fellas: as a friend of mine likes to say, “pay now or pay later: it all evens out in the end.”