Is the Bel-Ray oil just too thick until it gets up to temp?
NO
Assumption here is that you correctly reconnected the oil lines with nothing reversed or kinked:
1-Swingarm vent tube clogged or collapsed.
2-Swingarm internal vent tube dislodged or snapped off.
3-Oiling system air-bound(most common cause).
4-Engine had dramatically "wet-sumped" prior to lines being removed.
Check SM sections 3.9 thru 3.17 inclusive to confirm line routing and additional info. Manual is for 2009 but oiling info same as your 2010.
If simply an AIR-BOUND oiling system that has also "sumped", then do this:
completely drain swingarm
leave swingarm drain plug removed
install swingarm fill cap
crank and start motor and let idle for 5-7 seconds max
let swingarm fully drain then replace drain plug
add max of 2 quarts engine oil
do NOT replace swingarm fill cap
start engine-check for oil pressure-check for visible oil circulation in swingarm-check for air being vented from fill cap
replace swingarm fill cap and run engine and now see if resolved
If now ok then ride approx 5 miles to get bit of heat into engine...stop...park on sidestand...wait 30 seconds...check oil level....top off as required
http://buellmods.com/content/downloa...ice_manual.pdf