The following are tips on maintenance items to keep your XJ 900 in top riding condition. Also included are vendors where you can purchase needed replacment parts. Many of the following recommendations are from myself or Matthew Wiley. Matthew Wiley is the leading tech for all things XJ 900. He has amassed over 200,000 miles on his 900 Seca and currently writes tech advice in leading motorcycle publications. Mr. Wiley currently serves as Operations Manager for Race Tech, the industry leader in motorcycle suspension tuning and replacement.
Wheel Bearings - if your restoring or have over 25,000 miles on your 900, replace wheel bearings. Simple to do. Simply pull front or rear axle bolt and replace. Use water resistance wheel bearing grease when installing. Replacement parts at moto-service.net
Forks - replace fork springs. That's it. Just do it. Flush and clean internals. If fork tubes have rust pitting as mine did, replace with Forking by Franks. Replace fork seals and dust seals - moto-service.net
Steering Head Bearings - Replace. The ones in your bike are 25 years old. I tried the short cut and didn't replace. At freeway speed it got plain scary. Replace - oldbikebarn.com
Cables - oil at least once a year. Use a cable oiler - your local motorcycle shop should have them for sale. If cables are shot and need replacement check out Auburn Motorcycle Repair @ (253) 939-6666
Instrument Repair - contact me through website and can give estimate of repairs. If internals are damaged, your out of luck.
Gas Tank - probably needs to have inside of tank cleaned, rust removed, and coated. Several companies sell product, or contact me through website and can give estimate for cleaning and coating with my local gas tank repair folks. Google gas tank coating for web products.
Frame Repair - this is a big deal folks. Frames of this vintage were built of mild steel and just a tip over in your garage can bend, dent or twist them. When you buy a XJ 900 and it shows any tip over, or lay down damage, don't buy until you have frame inspected for alignment. Your local motorcycle race guys know who can do this.
Motor - pretty much bullet proof. Matthew Wiley says to simply change the oil, perform scheduled tune ups and ride the wheels off. I have put over 70,000 miles on Seca's and have never had a failure of any type.
Electrical - when the brush's in alternator fail, replace them. Mine haven't. Stator may fail in the 25,000 to 30,000 mile mark. Several aftermarket companies now on web do sell replacement. Connection at fuse block are weak. Replace with Radio Shack style fuse block. I don't even bother trying to restore Seca's without performing this repair first. If the Seca your considering for purchase has spent lots of time outdoors.....first burn a $1000 dollars, don't write me, and don't call home. Move on. Second thought, call me and I'll buy it for parts.
Transmission - The XJ 900 has the same transmission, except for ratio's, as the XJ 650 Turbo Seca. Yamaha built these transmissions to withstand the excess forces of the turbo...very tough. Have never come across a failed tranny. Easy to spot if a problem. If you don't find second gear, you have a problem.
Clutch - same as Turbo's. Slipping, replace - oldbikebarn.com
Rear Shocks - I have the hook up to rebuild oem's. Contact me through website. Replace - racetech.com On the cheap - hagons.com
Brakes - replace oem lines with new stainless steel lines. Rebuild front and rear master cylinders. Rebuild calipers with new pistons and "o" rings. Flush system. Add new brake fluid and pads. Skip all of above if you desire full body cast and nurse named Elnor. Rotors warped or galled, replace. Just in....hot tip from Matthew Wiley...replace your front master brake cylinder with a unit from a late model Yamaha FJ1200. The bore is bigger on the FJ1200 and gives added stopping power for the 900. moto-service.net
Shaft drive - clean and lube splines at u-joints and hub with every tire change. Drain and refresh gear lube oil every 12,000 miles
Bodywork - I can repair most plastic body work for motorcycles. Write for estimates - prototype900turbo.com
Missing parts - eBay, Craigslist, prototype900turbo.com
Exhaust Pipes - prototype900turbo.com
Until we post our catalog of replacement parts, please contact us through website with requests for parts.