The Euro Zone

Origins

This XV920RJ enclosed chain-drive was bought new off a showroom floor in 1985. This was before motorcycle manufacturers had their dealers destroy unsold models of previous vintage. It is registered as an '82. This model was affectionately known to its owners as a "Euro" -- in homage to the TR1 model so popular in Great Britain, South Africa, and Australia. One way to raise the ire of an owner was to call his ride a Virago. It broke my heart when Yamaha started to label the microfiche for this bike as "XV920R Virago." The bike was poorly marketed and lasted a mere two model years, left-overs were avavailible for special order until at least 1987. A really major problem was pricing: in '82 a Euro MSRP'd at $3695. Most 900 fours were much cheaper -- in fact Yamaha's XJ900 four retailed for $3295. Which bike do you think they sold more of? Not enough Brit bike enthusiasts and Ducati wannabes could or would pay that much for a bike that you needed to pour another thousand into to get adequate performance from. Throughout this site R, XV920R, Euro, and chain-drive shall be used inter-changeably.

The stats of the XV "Virago" series are monotonous. I exclude aberrations such as the 125, 250, 500, and 535. The 700, 750, 920, and 1000 had the same stroke: 69.2mm. The 920, 1000, and 1100 all had the same valve sizes: 47mm intake, 39mm exhaust. There is some discussion whether the R model had smaller valves than the Virago; Hanes manuals state that they had 43 intake and 37 exhaust as does Motorcylist Magazine of May, 1981. However, when I first pulled the top-end on my chain-drive it had 47 and 39 respectively. All had the same size carburators: 40mm, Hitachi for the smaller bikes, Mikuni for the later 1100. The cams were interchangable throughout the line, with the 750 and 920 getting: 401" lift, 245 degrees duration intake, 247 exhaust; the 1000 and 1100 had: .391 lift, 235 degrees both. The 920 had a bore of 92mm, the 1000 and 1100 both had 95mm bores. Thousand pistons bored right into 920 cyclinders, but due to the thickness of the thousand sleeves, using its cylinders as well required boring the 920 cases. Boring 920 cylinders to 1000 pistons yielded a displacement of 980cc - the same of the much lusted after TR1 - and bumped the compression up half a point due to the greater swept volume. The 1100 had a stroke of 75mm; it actually displaced 1063cc. To keep engine height the same the pin bore was raised 2.9mm. To get that displacement out of the 920, one had to bore the cases for the larger sleeve (or just bore the stock sleeves as deck height is identical throughout the line) and trim the windage tray for the larger crank to clear.

As soon as I acquired my Euro I installed the larger size Krauser detachable bags and trunk, a frame-mounted rear fender, Progressive (brand) fork springs and rear shock spring. I then looked to increase horsepower. At the time I worked in the motorcycle industry myself - at the nation's fastest growing Honda dealership. A half block up the street was a prosperous Yamaha dealership; not the one I bought my bike from though. I had much pull throughout Orange County (CA). I got parts mostly below wholesale, machine work for free or trade, and a mechanic at the Yamaha dealership offered to donate his labor, provided we campaign the bike in the annual La Carrera race - from San Felipe to Ensenada along mostly unpaved roads. More

The heads were ported - which required little work as stock ports are quite large - and decked fifty thou. Installed were a MAC two-into-one exhaust - mostly because of its enormous inside diameter - and Megacycle's road race cams (.502 lift, 268 duration) plus spring kit with titanium tops (correction -- aluminum tops, the titanium were on back-order), 39mm oval slide smooth bore Keihin racing carbs, and a pair of 41mm (2mm oversize) exhaust valves meant to be used in XT500s. That was all that was available. We passed on a supposedly more robust clutch, which turned out to be okay as the stock setup was up to the job. Lastly it was bored to 1.0mm over (96mm) XV1000 pistons, bringing displacement to 1010cc; the pistons were clayed and cut to provide clearance. The increased compression caused the starter motor to spin without turning the engine; this was cured by staking the sun gear to the housing with a woodruff key, along with a liberal application of epoxy between them.

What can I say? It started instantly, had added power right from idle and pulled like a locomotive right up to 8900rpm - where the rev-limiter shut it down. It cornered as well as anything could with those spindly 37mm fork tubes. It dusted every twin it came against: big inch Harleys, modified Ducatis, whatever. It did wheelstands in the first three gears with just a quick twist of the throttle, and out-pulled 1000cc fours. It QM'd in the tens in the one forties -- I wish I could be more specific, but the time slips are long since lost and Orange County International Raceway is now a shopping center called the speculum - er, Spectrum.

Alas, a week before the race our rider missed a shift doing a plug chop up a freeway bridge -- motorcycle-friendly dynomometers being quite rare at the time -- causing one of the already-irreplacable exhaust valves to tap the rear piston, and bend, shearing off the trailing tensioner mount, cramming it between the cam sprockect and the head, breaking the drive pin out of the cam along with a lot of bearing surface, In short order the engine was torn down. A cam could not be had in time. A replacement valve did not exist, The Keihins disappeared. The Project was shelved. I rode that beast with stock cams, slightly modified stock carbs, and stock valves -- the big bore and big ports, and pipe remained -- for at least 100k miles (still out-pulling Harleys and Ducatis), before I tore it down to replace a leaking head gasket.

TOP