Bike dies after 3 hours, overheating?

[earlfor]

Listen to the Chef Man. Your condensers are bad.

That would be a good probability.

[850GT_Rider]

Remove the inline filter. They have been known to cause fuel starvation problems.

Did you do this yet? These bikes do not like inline filters.

[Guest]

Does your bike have points?
Could be your condensers crapping out when they get hot as others have pointed out in earlier posts.

[chuck hahn]

Blocked or pinched off vent line can slowly cause 'vapor lock" as it were from not allowing the bowls to equalize with atmospheric pressure. Can check by blowing into the vent lines to see if there air transfer. Some fuel may spill out the front of the carbs but that's normal with the check.