Your spark may be breaking down as the RPM’S come up. This happened with my Polaris which had a rev limiter on it also. So @06kfx440 may have a point. I was pointed in the direction of a faulty rev limiter on one of my bikes through the forum here. I purchased this spark tester and put it in line with the spark plug. Started and watched the spark break down/fail as I reved the bike. I removed the rev limiter and my problem was solved. Worth a shot and cheap enough to try. It’s also a good tool to have. Having ruled out the fuel system it may be time to start looking in the ignition system. Rev limiter bad pick up coil stator coil problem regulator cdi box 4 of the 5 above listed parts can be tested and the repair manual will explain as far as how and what numbers should be shown on the tester during this process. I attached a pic of the spark tester.

The saga of the fan continues. The Pin attempt in the fan shaft failed. I then moved on to trying to weld the fan hub to the fan shaft. I took it for a run the weld broke. Now it was truly F'ed. To recap the dealer price, they want $400 + CND for a replacement fan assembly. I searched all sorts of after market places and no one carried one. Ebay had some used ones but they were $120 USD + Conversion rate for something as old as what I have. I went to Amazon and eventually settled on this. amazon link What I found... and was amazed... was that the fan mounted to the Suzuki fan assembly bracket. I was prepared to manufacture my own mount conversions... It also came with "Harpoon mounts" (nylon zip tie like things that go straight through the rad. Anyways it mounted to the original bracket. It fit perfectly. Cut the electrical plug off replaced it with the Suzuki... all good. Let the quad heat up, thermo coupler kicked in the fan circuit, polarity was right... all was good.... Fan is under the circuit fuse rating. so I finally have a solid fan solution. $34 CND vs $400+ CND

dead electric 2004 arctic cat 400 4x4 auto wire was coroded off man in harness in front of regulator two red power wires where they join into one was pulling hair out on this start removing tape - low and behold problem solved

Yes, both clutches in your '86 are the same as an '88.