I took another test ride this weekend and I definetly have the bog. It ran perfect before the HC install. I can't ride it like this for long. It occurs from a low RPM, say less than 12 mph in first, when I quicky open the throttle to about half or 3/4 open. It stumbles along for a while, then gets over it and runs great, or so it seems to me. I don't know how to tell if it is rich at high RPM. Here are my settings for 2003 S model with CV carb - I ride at 2000-5500 feet 134 main 25 pilot Klien Extend. Fuel screw - Adjustment does not fix bog or affect idleing DJ Needle and Spring 3rd clip Stock E exhaust HC intake only. I have done some searching and it appears to be running rich. I don't understand why it only affects it at jumps off idle but it seems to run storng once it gets the RPM's up. Here are my questions: 1. Do you think it is running rich at all RPMs? 2. If I add a full yosh exhaust, will it fix the problem. I like this option Seems like it should since opening up the exhaust flow more air thus, less rich. 3. What jetting do you recommend? I have searched and some people fix it by using the 3rd clip, but I already on the 3rd clip. Other says the stock spring is the fix. The pilot is probably too big at 25 since the fual screw has no affect. What do you suggest? Thanks.