Used WRR issues

Hi, I bought a WR250R this weekend. I’ve ridden a  friends WR before and have owned several bikes now: 2 KLR650, KLX250, Husqvarna TR650, KTM690, TW200, and currently a KTM790R.

The bike I bought 2017 model is loaded with all the options I wanted, low miles 2810, and good price $4800. I rode it in the dark at 9 PM and bought it (long story but I’d checked out a 2019 KLX250 earlier in the day, didn’t like it, and drove 4 more hours for this WR). I didn’t get home until 1 AM Sunday.

Sunday morning after waking up, I start going over the bike. Cleaning it up and inventorying the box of take off parts. Original Exhaust, smog delete parts, turn signals, etc. I found that the stock radiator was replaced as well. The original owner seemed excessive with lowering the weight as passenger pegs, all reflectors, helmet lock, and anything else not required was removed. Even turn signals but they were included so it wasn’t a huge issue for me. The radiator overflow reservoir was also taken off - that is a little concerning.

It rides and sounds great with a FMF power code slip on and the tuner controller. So, after changing the air filter to a new UNI brand, I ride it again and the little red check engine light is on. I watched a YouTube video and ran the diagnostic - nothing was showing.

My questions are 1) is the light on due to the smog delete and the seller may have cancelled it? 2) should I be concerned with the coolant reservoir delete? I have the bottle to replace if needed. 3) I’m in California, will a dealer work on this bike with all these mods?

Also, this is my first post here, Hi, I’m Mike! Thanks for any feedback.

You mean Diagnostic Page 61 does not show any codes, and Diagnostic Page 62 shows zero?

To answer your specific questions:

1. If smog delete was done correctly you shouldn't have any fault codes, and apparently you didn't because the CEL was not on during your test ride, right?
2. How can one delete the coolant reservoir? Where does the excess coolant go when the engine heats up? Yes, I would be very concerned and would attempt to reinstall the reservoir immediately.
3. They may, but they will charge you accordingly.

Thanks for the reply,Johnkol. I’m not sure the page 61 or 62. I was rushed when I ran the test. I really haven’t looked at the bike since Sunday. I’ve been working on a different bike. But I am sure there was no red check engine light on the first couple rides on it. The bike starts easy and seems to run strong. I’ll get it checked out soon enough.