im a dummy. what is the difference between these?

 

No difference, except the spelling, but TRX250R is more correct. As you probably know by your login name, the ATC250R is the 3 wheeler.

 

I don't think that's what he meant. 250R 4-wheelers are sometimes called the "250R fourtrax" and sometimes called the "TRX250R".
ERIC

 

The full name is Honda TRX250R Fourtrax. It just depends on how much of the name you want to use. Some use TRX250R, 250R Fourtrax, 250R, or just 'R'. But when ordering parts, be careful, the suzuki quadracer is the LT250.