(Severe Damage) Polaris 400 Engine rebuild Part 2

[@MrFixit1]

Broken piston skirt is the most common reason for this crank case damage.

[@mkuehn5450]

Excellent video. sorry about your loss (of the case). i'm nearly finished a train wreck of a 92 350l 4x4. top end was off a chicken spit covered barn find. "free" but $800+ later, it's done. one thing i'd add to your inspection. the balance shaft WILL wear grooves right where the water pump seal rides. i got lucky and found a good replacement, but don't neglect changing that seal. i went with an allballs bearing set, gaskets and seals, piston and rings, rehone, replaced the balance shaft, a starter (of course) had no exhaust or seat. rebuilt the cooling fan and replaced the radiator switch, Noticed the switch in your head was broken, it's for an overheat light. also cleaned and lubricated the brakes and bled fully. stacked rubber bushings on a bolt for the bottom motor mount. fabricobbled a head to frame bracket. from your maintenance video, my speedo shaft was sheared, so i flattened 4 sides of a tiny bolt as a replacement, as well as replacing the cable. spent $15 for one strut pivot ball as it was held in by truck inner tube, prior owner. i ended up removing my chain adjuster eccentrics to clean and anti seize. replaced the bottom steering shaft bushing. for the transmission, i went with 90w, as i read i could use atf, 30w or gear oil. ground the rust off the rim bead areas and painted. i used ATF in the front hubs, waiting on new front control arm bushings.

[@MrFixit1]

Wow, sounds like you had to fix or replace just about everything. Thanks for sharing your journey and experience with this quad.