Stutter at full throttle.

[andmoon]

Before getting involved with motorcycles, we all heard that, with respect to air filters, the more free flowing and less restrictive, the better. That might be true on lawnmowers and cars, but with motorcycles the situation is different. Most motorcycles run poorly if the stock restriction levels are reduced. What happens is that they lean-out at higher RPM's because the vacuum is too low to suck fuel up the main jet. I know it sounds counter-intuitive, but sometimes you have to increase the intake resistance slightly (more oil on the foam, thicker foam), to keep the vacuum needed at RPM's above 4000. My bike will not run worth anything with the air filter off, but it runs perfect once re-installed. I tried using free-flowing pod filters, but the performance was worse than with the stock arrangement.

My bike has stock intake and to see if it was an intake issue, I ran the bike w/out the filter and w/ 1/2 the intake snorkle blocked off.