Most likely it is the stock starter at those miles. Since it starts fine with jump, most likely battery. get it load tested, or look for a date on the battery. Do you leave it on a tender? If so, don't for a week, and see if it starts. If you are in a winter climate, buy a battery in the spring. Granted it would be nice to figure this out so you can go for a ride, or work on it over the winter.

The reason I asked if it was a built motor, which it is not, sometimes they need compression releases or bigger starters.

In a non hot area a battery should last 5-7 years, less down south. if the date is around there, I would replace.

Other option is to check connections, in case a little loose which and not enough voltage when hot. But other than battery cables themselve, I would not waste a lot of time on this yet.

 

I will get the battery load tested and no I don't have a tender but sometimes it starts fine after a week and sometimes don't I remove the negative terminal from the battrey as I don't ride my bike daily
Will surely check for loose connections

 

If you are saying sometimes it does not start after a week, I would not waste time on anything else, just get a battery. Unless you have a secruity system. But even my bike with a fob starts after a week.

When it doesn't start, how long does it sit?

You jump it, it starts Kind of says something doesn't it. Unless you have some reason to believe it is the charging system. Which I doubt at 26k miles. Put it on charger over night, leave it for a week. If it does not start get a battery.

Always check the cables at the battery, it is free and easy.