900
Well, I bought a 2005 900 RMK 3 years ago with 800 miles on it for $2600 in Tahoe from a kid who needed rent money. He was the second owner. It was basically stock other than an SLP can and reflash. I did all the upgrades that the Forum here and Mountainhorse suggested (some he actually helped me with since he lives up the road from me). Those upgrades consisted of:
1. New helix, 66-44 ER .46/66-42ER .46
2. New driven clutch spring, red/pink
3. New Delrin washers in driven clutch
4. New primary clutch weights, 10-70
5. New primary clutch spring, Polaris almond/Team green
6. Clutch balanced by Indy Dan with bushings replaced
7. Jackshaft bearings replaced with new
8. Torque stop replaced with new, OEM
9. Intake throttle body boots replaced with new, Kimpex
10. Front and rear motor mounts replaced with new OEM 2006 mounts
11. Thermostat replaced
12. Injectors sent to Witchunter Performance for cleaning and flow test
13. Installed 08 Dragon spindles
14. Set chamber and toe with new spindles
15. Installed 225# track spring and adjusted limiter straps to full loose
16. Install new fuel filter
17. Changed gearing to 18/40 (new gears same chain)
18. Changed gear case oil, Polaris synthetic
19. Installed new float sending unit in fuel tank
20. Installed refurbished mag-side cylinder (Nikasil was bad in old one)
21. Installed new OEM 2006 pistons, rings, clips and pins
22. Install new throttle/oil cable, Motion Pro similar to FBF cable
23. Install new hyfaxes and adjust track tension
24. Fabricate and install intake boot heat shield
25. Installed two vent screens
26. Install 3211115 Polaris belt
I probably did other upgrades too but can't remember them all. I do the yearly regular maintenance items like lube the chassis, clean the VES, adjust the track etc.
I have almost 3200 miles on it now and I've never seen so much as a single problem with it. My 11 year old son and I go out 40 to 50 miles in the Sierra's every other weekend during the 5-6 month season here and do at least 75 miles per day. I too have towed back many other sleds including others of mine (not 900's).
In fact I bought my new 2012 Pro RMK 163 for others to ride when I take people besides my son and I. I'll stick to my beloved 900 and may only ride the Pro once in a while.
Mountainhorse once told me that if you do all the upgrades to the 900, it will be as reliable as any other sled out there. He was right as far as I'm concerned!
John