Spark plug ? W/turbo xp

Ok, so i am confused about what the diff in spark plug gap does. I have a turbo xp, the first day i rode it i was putting around being easy on it and fouled a set of plugs, with out knowing i grabbed some plugs from a buddy on a xp and took off. 640 miles later and some r&d the sled has been awsome, except for a little bottom end bog. (loads up at a idle) Last night i was putting some high torque rollers in and just checkin things out and pulled my pluggs and seen that tha ones in it were differnt than the ones that wre in it when i bought it. I called and was told to run the ones gapped at 17,000 and the ones that i borrowed were 30,000 so i put a new set of 17's back in and it fowled them quickly. put 30's in and back to normal. so if still a little rich can i change gap to maybee 35 or so? stock 17.5 pilots are in it now.

I have leaned the screw to almost closed and noticed a little imp. but get a lean pop on top end, mid range and top end run best with screw about 1 to 1.5 turns out. and 2t at low elevation.

Rode this weekend and tried plugs gapped at 35 not any better than ones at30 so i put the thirtys back in. should i try a smaller pilot jet when i pull the plugs after shutting off at a idle they are plenty wet.