When I uncovered the bike yesterday before my ride, the smell of raw fuel hit me. I broke out the spotlight and checked every nook and cranny and didn't see a drop anywhere. Actually, the tank was near empty from the previous days ride, so I stopped to fill up.

After riding to the reservoir about 10 miles away, I stopped to enjoy the scenery and smelled it again. When I got home I opened the oil fill screw and stuck my pinky in there and soaked it with oil. Oil seemed fine and didn't smell like fuel at all, but when checking the oil about 15 minutes later, I did notice that the oil window showed the oil was just above the high mark.

I checked the oil the day before and it was just below the high mark, but I checked it after firing it up and letting it run for 5 minutes before I went riding. I checked it yesterday after a 2 hour ride and 15 minute sit time.

I'm a bit concerned that fuel may be making it's way into the oil.
When I get home from work today I'm going to:
1) check the air filter for fuel smell.
2) check the carb vacuum hose for traces of fuel.
3) Before my next ride I'm going to buy a couple more quarts of oil and change the oil/filter. I did my last oil change about 1000 miles ago, but the cost will be worth it. Better safe than sorry.

Any other comments or suggestions would be appreciated.

The bike is running fantastic right now and I want to keep it that way.

& drain the gunk hose

I just did the manual petcock.  You need the petcock from a 2003 Yamaha Raptor 660.  Got mine from Ron Ayers for $2x.00 and works great.  

-Take off both gas lines from stock petcock (vac line and reg. line) and take off gas tank and drain gas out (inspect inside for signs of gunk, gook, shellac or rust)  If you find any of these, fix it immediately or it will haunt you forever!
-Remove stock petcock from under tank via 2 screws.  Keep the screws.
-Install the raptor petcock and make sure it's in the OFF position
-Install a vac line plug (got mine at Advace for $2 for a 5 pack-think I got the 5.5 mm ones)
-Reinstall tank on bike and hook up front gas line to raptor petcock (not the line you removed with the spring on it, thats the vac line you need to remove completely)
-Put gas back in the tank
-Turn petcock to ON position and let it sit for 10-15 seconds for float bowl to fill up
-Crank her up!

p.s. This mod was very easy and cures the dreaded leaky vac line a lot of people seem to be having.

p.p.s  You CANNOT forget to turn the new raptor petcock OFF after you shut your engine off and ON before you start the motor.  

HTH anyone wanting to do this mod...

-Matt

When this happened to me, the smell of raw gas came from a small leak in the tank, had to kream the darn thing.

I occasionlly smell a little raw fuel. I think the post about temp changes and tank venting is spot on. I've got no leak, no fuel in the oil, no drop in mileage, no obvious trail of gas.  Just the odor. What I do have are some pretty big swings in temp. Not only from ambient temps day to day; but from outside to inside my garage on any given day.