cooling not so cool

A couple things...

You only want about an inch of fan "max" inside the shroud. Many will say 1/2" max.


You might have a timing issue if it now always climbs to overheat, where as before it would cool once in motion from those warm ups while sitting at a light.
Start there and then adjust the fan accordingly. They might have raised the intial but skipped the other end "full advance"and that will have it in an unrecoverable position in no time. I didnt include the cap because if what you said...but it would not hurt to replace it with one 2-4lbs higher rating.

Thats a start, not a guaranteed fix.