A repost by our friend Robert, from his facebook post.
Take it away Robert.
Gifny Richata's and Greg Criger's (http://xs500.blogspot.com/) recent posts in our group made me dig deep in my XS500 archive of information collected via the Web over the years. Here is a source from email@example.com (unfortunately, I could not contact him under this address). When I found this piece in early 2004, Dave wrote "This page was last updated on 22 May 2003." Hopefully, it is still useful for many of you readers. "YAMAHA'S MATHEMATICAL MASTERPIECE" That's how Motor Cycle News described the Yamaha XS500 in June 1976.
A few years ago I bought a Yamaha XS500, not really knowing anything about the model. After numerous phone calls I realised that very little information was available, so I decided to create this website. The XS500 was first introduced into the USA in 1972 as the TX500, and became the TX500A in 1973. The TX models were later re-designated XS to give the four stroke engine models a more positive identification. When the XS500B was first imported into the UK in 1975 it was the only production bike in the world to boast of twin overhead camshafts and four valves per cylinder. In addition to this advanced design, the XS500B was also fitted with another Yamaha innovation, a chain driven contra-rotating crankshaft balancer to eliminate the effects of engine vibration experienced with four stoke twin cylinder engines.
The early XS500 closely resembled the XS650 twin sharing many of the cycle parts but underwent restyling in 1976, which saw the rounded tank design replaced with the square tank and side panel styling, common with the XS250 and XS400 twins. Despite the "advanced" engine design, in the late seventies the bike was up against stiff opposition from the other Japanese manufactures and the XS500 was finally dropped from the range in 1981. To the best of my knowledge the information in these pages is correct. If I have made any errors, or you have any comments, information, pictures or brochures that could be included in these pages please e-mail me at the address below. firstname.lastname@example.org [Since his e-mail address is off, please post anything that you know or would like to correct to this group and to Greg's blog (http://xs500.blogspot.com/),or http://xs500.proboards.com/ thank YOU]
Model TX500 Year 1972 Model Code Europe 371- Model Code USA 371- TX500A 1973 371- 371- (img:1955118790906) XS500B 1974 371- 371- (img:1955120750955) XS500C 1976 - 1H2-0 1J2-0 (img:1955127391121) XS500D 1H2-1 1J2-1 XS500E - 1981 1H2-2 1J2-2 (img:1955130591201) XS500C Facts Engine 498cc (73 x 59.6mm) double overhead camshaft, 180deg parallel twin with four valves per cylinder. Light alloy cylinder block and head with cast iron cylinder liners. Wet sump lubrication. Compression ratio, 8.5 to 1. Claimed maximum power, 48bhp @ 8,500rpm. Carburettors Twin 38mm Mikuni CV with lever operated cold start jets, fed from seperate fuel taps (one either side of tank). Paper element air filter.
Transmission Wet multiplate clutch and five speed gearbox. Final drive by 5/8 x 3/8 chain. Ratio - 17 front, 43 rear. Electrics Coil ignition with 12 Volt, 14 Ampere hour battery and 130 Watt alternator. Tyres Front - 3.25 x 19, Rear - 4.00 x 18 Brakes Hydraulically operated disc with floating caliper. Front - 11.8" dia, Rear - 10.4" dia. Frame Welded and gusseted duplex tube cradle. Suspension Telescopic front fork. Ted Cichocki added information, June 17, 2011: Fork Tube Diameters 34mm Yamaha TX-500/A/ XS-500B (73-75) 35mm Yamaha XS-500 C/D/E (76-78 ) Pivoted rear fork with spring preload adjustment. Front Axle Diameter 17mm XS500 76-78 Rear Axle Diameter 20mm XS500 76-78 Dimensions Wheelbase 55" 1397mm Seat height 33" 838mm Ground clearance 7" 178mm Turning circle 15' 6" 4724mm Castor angle 62.5deg, Trail 4.6" 117mm Weight (inc 1gallon of fuel) 448lb 203Kgs Tank capacity 3.2 gallons 14.6 litres Price (New) GB£ 839 inc vat in 1976
ENGINE and other Facts VALVE CLEARANCES (cold) Inlet 0.15 - 0.20 mm Exhaust 0.20 - 0.25 mm BALANCE CHAIN Free play 5 - 7 mm ENGINE OIL Capacity 3.0 litres Grade 20W/40 TYRES FRONT Size 3.25 x 19 4PR Pressures 23 psi (1.6 kg/cm2) normal 28 psi (2.0 kg/cm2) high speed riding REAR Size 3.50 x 18 4PR TX500/XS500B 4.00 x 18 4PR XS500C/D/E Pressures 28 psi (2.0 kg/cm2) normal 33 psi (2.3 kg/cm2) high speed riding IGNITION SPARK PLUGS Type NGK - DR8ES DENSO - X24ESR-U Gap 0.6 - 0.7 mm CONTACT BREAKERS Part No - Left 371-81621-10 Part No - Right 371-81622-10 Gap 0.30 - 0.45 mm FRONT FORKS OIL Capacity 147cc Grade 10W/30 ELECTRICAL BATTERY Rating 12V 14Ah Types GS - 12N14-3A YUASA - YB14-L BULBS Headlamp 50/40 watt Tail lamp 8 watt Stop lamp 23 watt Flasher lamps 27 watt Flasher indicator lamp 3 watt Neutral indicator lamp 3 watt High beam indicator lamp 3 watt Speedometer lamp 3 watt Tachometer lamp 3 watt FUSES Main fuse 20 amp Ignition circuit 10 amp Flashing indicators 10 amp Lighting circuit 10 amp Spare fuses 10 amp & 20 amp
Technical tips Balance Chain Watch the tension! The balance chain tension needs to be checked on a regular basis. Neglecting the chain tension will result in wear to the sprocket fitted to the end of the crankshaft. This will require a complete engine strip to repair. Crankcase Cover Gaskets The parts book for the 371- and 1H2- models have the part numbers for the crankcase cover gaskets transposed. The part numbers according to the parts book are shown below. Its probaly safer to state which side you need a gasket for and not just quote the part number. Crankcase Cover Gasket Part Numbers 371- Parts Book Left hand cover = 371-15462-02 Right hand cover = 371-15451-01 1H2- Parts Book Left hand cover =371-15451-01 Right hand cover = 371-15451-02
Oil Filters The original oil filter is no longer available, although some dealers are known to have a few on their shelves. An alternative is to fit the replacement filter kit from Yamaha. This consists of a new filter mounting boss, together with a standard oil filter as fitted to the FZR600 / XJ600. The only problem that I have found is that the left hand crankcase cover has to be removed to permit replacement of the oil filter – however, use this as a good opportunity to check and adjust the balance chain tension. Part Number 3FV-13440-00 Description ELEMENT ASSY, OIL CLEANER 371-13447-09 COVER, ELEMENT 371-13449-01 GASKET, ELEMENT COVER 90201-422F3 WASHER PLATE (12R) 93210-48460 O-RING (4U8) Sadly, Yamaha have superceded the oil filter to new part no "3FV-13440-10", which is now too tall to fit under the cover. Yamaha admit that this is so, as apart from the XS500, on most other bikes the filter fits externally, where height is not an issue. You need to look out for "New, Old Stock" filters - or dink in the end so it fits. (Thanks to Andy Sochanik for this info)
Wiring Diagram The wiring diagram in the Haynes manual for the XS500C does not appear to be correct. The XS500C wiring diagram in the Clymer manual is OK. ThanXS, Dave, for putting all this together and letting us share it. Gratefully yours, Robert
Thanks for sharing this info Robert.