You do not state what mapping program you use. If it is Mapsource, to to Track Properties and then click the Filter button. It will become clear from there.
See user manual page 44.
You can set the max number of trackpoints per track.
The unit will only store a max of 10,000 trackpoints.
The unit has a max of 20 stored tracks so default is probably 500 points max.
I am guessing but it looks like if you set the max trackpoints to 5,000 then you will only be able to store 2 tracks.
Sorry. I'm using Base Camp on a Mac.
Actually I have the track points set to 10,000. Even with this setting I'm only able to install (from my comp) tracks with a max of 500 points. I've tried to download tracks from wikiloc.com and have had success. Wikiloc gives you options to trim (simplify) the points or split the track into <500 segments.
I'm just beginning to learn all of this.
Thanks for the replies,
Rob