I bought the Novak Velociti 5.5R Brushless Motor System for my sons b44. I have a question about the speed controller. It has a small fan on the heat sink. Is this fan necessary? It gets clogged repeatedly with leaves and small twigs and will locked up all the time due to this. I have yet to have a overheating issue, but this weekend, I will be upgrading to a lipo battery system. Will increased power create a heat issue with this unit if the heatsink fan continues to fail? Thanks

NovakTwo may differ in response. So take his word over mine.

Fan Issue:
If the fan is getting clogged and stalling, I would remove the fan. The stalled fan could overload the BEC circut and cause a meltdown in the ESC.

Motor issue:
Removing the fan really isn't an option for higher powered motors. Your 5.5 is a higher powered motor and would need a fan.

Your only option would be to keep debris from entering the fan.

Take a pice of .030 lexan and make holes so you can screw it on top of the fan. Then drill a series of 3/32" to 1/8" so it looks like a chain link fence (almost all holes in a neat, geometric pattern). That will keep out debris that could jam the fan. You will need longer screws to attach the lexan and the fan to the controller heatsink and spacers so the lexan doesn't touch the fan blade. Even motor shims will do the job to keep the lexan off the blade.

I was lazy and used a piece of the perforated aluminum you sometimes see used for enclosures on electronic equipment. Also, I did it for a fan on an HV-MAXX, not a GTB, but the principle is the same. Don't ask where I got the aluminum - it is a couple decades old.

Running a 5.5 without the fan could cause a melt down in the esc the fan was put there for cooling so I would'nt run with out it.

Go to the store and buy a pack of ladies panty hose (ignore the weird looks you will get!)
Then cut out small squares and use your hot glue gun to put a dab of glue on each outside corner of the fan and stretch the stocking square over the fan - it acts as a simple filter but the mesh is fine enough to not restrict airflow.

Don't buy fishnets - just regular hose will do.