 |
Motorcycle Data Sheet Model: 1976 BMW R90/6 Engine: 898cc 2-valve boxer twin (60 HP) Years of Production: 1974-1976 Number Produced: 21,070 Purchase Date: December 2002 Previous Location: Seattle, WA Previous Owners: 2 Mileage at Purchase: 71,000 Mileage to Date: 71,500 Restoration Projection: $5,700 Restoration Costs to Date: $3,700 Restor-o-meter:
|
I was lucky enough to buy this motorcycle from a really nice guy in my old neighborhood. Even though it wasn't quite running when I bought it in December 2002, everyone with whom I spoke advised me to go for it because the 90/6s were really great bikes.
The motorcycle had not been cranked for the better part of a year, so the first thing I did was strip the bike down. I sold the unwanted Vetter fairing and Krauser cylinder guards, and I pulled the tattered bench seat and broken pannier racks off the frame. Because of the fairing removal, the motorcycle was missing some key parts to the turn signals and headlight bucket, which would require ordering. The front fender was cracked, so I tossed that too, reserving the hardware for resale. I also removed the tank and drained it of fouled gas, as I did for the carburetor float bowls. Then I changed the oil.
Of course, "proper" is a fairly inaccurate term to apply to that first ride. I had to bring a borrowed /6 small tank full of gas with me in order to ride it home, as the /7 sports tank (very similar to the coveted 90S tank with the same shape and a raised fuel cap) needed complete refurbishment. Since the nipple on the right fuel petcock was missing, I had run fuel from the left tap through the crossover, pinch off the right-side line, and seal the system with duct tape! I also brought a bulbless headlamp to press into place in the hopes of reducing my risk of police predation (my tabs were expired), also held fast by a good wrap of the sticky silver stuff. My front turn signal-less mount, still ailing from the removal of the ugly Vetter fairing, did fire right up, though it idled weakly without new piston rings and misfired at odd intervals until warm. Regardless, it got me home without incident (including without traffic citation). It was on the trip home that I noticed that the forks were tweaked -- something I had missed with the fairing in place -- and would need attention and/or replacement at some later date. Even with this damage and the rough-running motor, it pulled with obvious strength and clearly demonstrated the character of a superior motorcycle in the making. I was very happy. She may have been a long way off from the superbike of which I had been dreaming, but at least she was now up and running!
With the help of my friend Howard, in May 2003 I installed short-shroud shocks and the /7 subframe, as well as alloy-body rear turn signals. (The front of the bike still lacked blinker stalks!) I also found a pair of oversize 898cc high-compression pistons (ratio = 9.5:1 as per the R90S engine) on eBay, for about half off the list price, which I boxed with my 33/11 final drive, awaiting future installation. My penultimate major coup in the process of parts acquisition was the double disc front fork and brakeset (i.e., everything but the rotors) in June 2003. With all the 90S bodywork save for the fairing shell awaiting paint renewal, I lacked only the quirky Dell'Orto carbs for my complete mechanical upgrade to 90S spec.
As spring 2003 transitioned into summer, I had my first real "catostrophic" maintenance issue on any of my Airhead bikes; with relatively little warning the transmission input shaft on this motorcycle gave up the ghost, apparently stripped, leaving the engine purring beautifully but transmitting nothing to the rear wheel in any gear. As a result, the bike was laid up for and largely neglected for the better part of a year! With some luck I was able to source a reliable replacement five-speed transmission from a 1978 /7 bike at a very reasonable price from a local enthusiast.
With other bike projects and more practical matters at hand, the drydock for the R90/6 that started as weekes and turned to months ended up being a full year, including a rainy winter parked (covered) outside on the street before I finally hauled it to my mechanic, Mick Vallantine, in August 2004 for major service, which included engine upgrades, a new front fork to cure the tracking problem, and dual front disc brakes, in addition to a new gearbox.
During the bike's time in drydock for the transmission trouble, I successfully sourced an NOS fibergalss replica S-style bikini fairing and an original R90S sports tank (with the correct raised gas cap). The tank wasn't as cost-effective as the lookalike /7 tank I had found at the start of the year, but as the scope of my restoration had grown from a cosmetic upgrade to a virtually complete match of the original 90S equipment, the proper tank bacame a more appropriate choice. I even found a pair of refurbished original R90S handlebar mounts in satin black with polished stripes at Joshua Buck's Parts Haus in Southern California. Eventually, after several bizarre turn of events, I also happened on a cheap OEM fairing shell (and reserved the aftermarket replica for another bike), so I could use genuine 90S parts all around.
To bring the R90/6 touring engine up to R90S specification, the 900cc cylinders were bored to the first oversize (90.47mm) to match my high-compression pistons by Jim at Hill Machine in Seattle, while the heads were inspected and renewed by Dan at the companion shop, Hill Machine Headworks. These services were completed for well under $200. At this same time, I lucked into a thoroughly reconditioned pair of 38mm Dell'Orto carbs at an affordable price on eBay, the last of the signature items I needed for the complete S upgrade. I still have to install the carbs, though and in September 2004 I did some minor maintenance on the 32mm Bing CV units to keep them running right.
In addition to installing the Dell'Orto carbs, the next item on the to-do list for this 900 is getting the S bodywork restored and painted in preparation for installation. Although I had been planing to restore the bodywork for this bike in one of the original R90/6 colors to avoid having anyone confuse my "cooked superbike" with the real thing, of late I have been lured by the siren's song of the 90S's fancy two-tone fades, Daytona Orange and Silver Smoke. I have decided on a Daytona Orange paint job by Charlie Moore, the skilled painter and owner of Tanks Only here in Seattle. I have seen his two-tone restoration work on a local R90S (below left), and it is fantastic.
April 2003
Thanks to the following individuals and companies for assisting in this restoration project: Howard Bialik, Barbara Bynum, Fred Inman, Peter Locke, Mike Mabie, Charlie Moore, DL Powers, Blake Richardson, Ride West BMW, Andrew Scudder, Bo Stewart, Chris Telford, and Mick Vallantine.
65%