I finished rebuilding the fuel injected engine (top end) on our 2008 Polaris 700 Dragon RMK Friday night. During the rebuild, I discovered the previous owner didn't use Loctite® on the exhaust valve guillotines and after we put just over 100 miles on the sled, they loosened up and started hitting the pistons causing the engine failure. A local dealer said the sled was basically junk without a repaired engine. They gave me an estimate of $1,500-$2,500, so I decided to tackle the project myself.