Just finished up doing the Marcelino Mod, on my 2019 KLX250 took me about 2-3X what you would expect. I wanted to insure that everything was done according to directions.
Actually side benefit was that I believe it even starts more easily. I bought the EJK tuner, but wanted to fire her up ;and go for a short spin to see if I could tell the difference. There is a difference for sure
certainly not overwhelming. I didn't remove the ACR , but the spring, if I understood correctly this negates the ACR, It was then that I hooked up the EJK unit which had a oxy sensor delete, getting that removed was the most
difficult part of the install. I didn't use the recommended grounding site, but grounded it at the negative battery cable. So now I am left with this floppy piece of electronic, and cables and am looking for someplace to mount it out olf sight .
Still running stock "escape" exhaust, but went lidless almost from the start. I have been looking around the chassis, trying to find a place, to fasten the LED plate, there was no two sided sticky velcro in the
package, but I am thinking possibly just place it in the air box between a couple pieces of foam rubber. What did any of you do. There may be some room behind one of the body panels. Instructions say it is "water
resistant", don't know how it would respond to being placed in a plastic sandwich bag for protection? Recommendations?

 

I removed the air box lid but intake roar was quite loud. I cut my lid in half and mounted the EJK to it with velcro. Once you get your set up done you prolly won't mess with the settings. I thought about mounting it to flat spot on right side of air box but I was worried about the header pipe proximity. I have a 2018 with K&N and FMF Q4 and use the stage ! settings.

Freakdaddy