The side panel on my 2007 KLX melted and stuck to the Dirtbagz saddlebags. The heat reflective material inside the side panel on my old bike dried out and the glue failed. The back section of this aluminum foil material fell off. This caused the plastic to melt from the muffler’s radiant heat. The forward section was also in pretty bad shape.

I bought some heat reflective tape material and relined the melted side cover. I will need to order a new side cover but for now the tape on the old melted cover will suffice.

While I was at it I also fabricated a second heat shield out of some stainless sheet metal. It bolts to the muffler mounts and is inside the plastic side shield.

Do yourself a favor and look at the integrity of the heat reflective material and its adhesive, especially if your bike is older. Four bucks worth of tape could save the cost of a $91 OEM part. Lucky for me the Dirtbagz were not hardly damaged (slight melting of the internal stiffening panel).

 

Sounds like your saddlebags may be to blame. Everyone has that foil fall off eventually.

 

My new plastics came with no foil, however the FMF tailpipe runs very cool. Most of the heat dissipates via the Megabomb before heating the muffler.
I put my stock header and pipe on the other day while cleaning and repacking the FMF. Took it for a spin and could not believe the heat generating from the stock tailpipe ( with Cat Converter). The whole rear subframe was too hot to touch after a 10 minute spin. Possibly an issue with the 331 kit being too much for the standard pipe?
If I left it like that I would certainly end up melting plastics and possibly anything else in the vicinity!
The 331 also felt sluggish with the standard pipe. Would not rev out past 8K.

 

The saddle bags no doubt contributed to my problem. The saddle bags have been on pretty much full time for over a year before the side panel melted. I have also had the KLX300 exhaust for much longer than that. Maybe the nearly 100F day temps in stop and go traffic were the root cause. But, after re-lining part of the side panel with heat reflective I felt the difference in covered and non-covered areas after a short ride. I think the heat reflective material is pretty effective.