To do the job right, anything in the way needs to come out. I repair front heat exchangers that are part of the bulkhead. I replace the exchangers that run along the tunnel, they are like $70 new and easier to replace than trying to get a repair to stay. The edges of the repair will have to be sandblasted slightly to rough it up so the JB bonds to it. Figure out some way to keep the sand out of it. You only need to blast it for a few seconds. I use Marine Tex quick set-3 to 5 minutes in 70 degrees. Put a heat lamp on it. Heat cures it faster. I have heard stories of improper bonding falling out and seeing some green and overheat. I have NEVER had a problem with a repair on the bulkhead cooler. I ALWAYS replace the tunnel coolers-the track rubs on them and debris is flyin by em too.
I have welded most damaged ones, however, some don't mind the epoxy fix.
I would grind the cooling fins flat around the area, then use a clay like epoxy. While it is still tacky, I use a liquid 2 stage epoxy to cover it up and it will bond to it. There are no chambers in the bulkhead cooler, so you can stuff the clay type into the hole and keep pushing it until it's flush with the hole, the spread your liquid quick set over it and it will bond to the repair and outer area. I have repaired several this way and have never had a leaker. The trick is make sure the prep area is roughed up and porous to ensure a nice bond. You will find it is easier to remove the suspension, track and driveshaft. It's a pain, but you will thank yourself(unless you are one heckuva contortionist) Good luck.
thanks for the help, is this a common problem it seems? i know 2 guys with the same kind of sled and both said their heat exchangers have been repaired at one point. i dont even remember doing it. the only thing i can think of was when i was crossing a road yesterday and on the other side is a ditch. i hit the throttle goin up the ditch and cuaght a little bit of air, but i wouldnt think that would be enuff to his the heat exchanger. doesnt polaris put the heat exchangers on the sides of the tunnel out of the way of the track?
Track too loose, too long studs, catch air, baloon the track, hit the brake, track studs hit the cooler. Any one of these combinations. Polaris has a cooler protector that rivets to the tunnel to protect the cooler. I am not sure if yours should have one.
I performed the same hack job on my old 96 Zr. I jb welded it to keep riding at the end of the season with the intent on fixing it for real the next summer.....never did and it worked fine. With proper time (aka no snow on the ground) I'd fix it properly. Seems like one more thing to go wrong.