get over your pipe hatred....pipe and prop, call it a day
Best two mods to my SXR were pipe and ignition. Period! Learn how to tune and install the pipe, or have someone else do it. I ran mine for years with no issues. The problem with stuff like aftermarket parts is the installer
Sounds like the pipes were never installed right. That includes jetting the carbs appropriately.
I can idle a long ways without fouling plugs my piped motor.
But, if you're dead set against pipes, plenty of good "non-pipe" advice has been given in this thread.
That's because the motor makes more power with a pipe. More power - more fuel.