[blueboy5000]

Unless you live in California, remove ALL of the emissions system. The Fuel-Re-Evaporator system can and does fail, quite often, causing annoying vapor-lock at best, and a fuel-flooded oil at worst. The Pulse Air system simply forces air into the exhaust directly, and when it inevitably fails, causes horrible back-firing and possibly will burn your muffler out and ruin the valves.

Leave the VENT HOSE from the gas tank OPEN, it shouldn't leak anything unless you are extremely over filled.

REMOVE the PAIR system and block-off the passage in the head with an NCY block-off plate or make your own. Attach the VALVE COVER OIL BREATHER HOSE to a suitable catch-can, or leave it open to the ground (leaving it open will allow a small amount of vapor and condensate oil to leak from the hose)

And lastly, if your fuel tank is mounted ABOVE the engine, eliminate the PETCOCK and replace it with a 3/16" MANUAL FUEL SWITCH from Briggs and Stratton.

These bikes are only 1 cylinder engines, and vacuum is at a premium, the less vacuum accessories you have, the better your bike runs.