We’ve received a number of email requests from readers asking for more project coverage in general and for more automotive project coverage specifically. Well, ask and you shall receive. This first Toolmonger “project garage” post will cover the beginning stages of one of the automotive projects we’re currently undertaking: the teardown and rebuild of a wrecked BMW “airhead.”
BMW fans refer to their line of horizontally-opposed-air-cooled-twin series of bikes as “airheads.” We came across this particular example — a 1976 R90/6 — as a “haul-it-off” special in the Fort Worth area. As best we can determine it was parked in “as wrecked” condition after an accident about five years ago. Apparently it was “t-boned” at low speed from the rider’s right. Though there’s certain to be some frame damage, the bike rolled straight and appeared surprisingly together considering what it’d been through.
Read on after the jump to see what we found when we got it back to shop and tore into it.
Though it does look quite good considering the accident, there’s no doubt that this bike has been seriously damaged. Worst of all, after sitting for years, the gas in the tank had separated, rendering it one of the stinkiest bikes we’ve come across.
The previous owner had added a ton of aftermarket items including a large Windjammer fairing, a large trunk boot, and a trailer hitch. The wiring on the hitch was nasty, chopped into the factory wiring harness in numerous locations. The hitch was bent, though we probably would have discarded it anyway.
Truth be told, we think turning the relatively sleek R90/6 — which is essentially the little brother of the R90S of racing fame — into a German Goldwing is heresy, so as we began tearing the bike down we placed it into four “piles:” the bike itself, large items we intend to keep (in storage during the rebuild), small items we intend to keep (in the shop during the rebuild), and items destined for the dumpster.
Starting the Teardown
Removing the busted fairing was easy, as was removing the trunk boot. Once they were gone you could immediately begin to see the lines that made these bikes so popular in the late 70s. We imagine that when we finally get this bike together we’ll opt for the slick bikini fairing.
The tank came off with a few bolts and some pulled fuel lines, and after numerous breaks for air we managed to clean out the spoiled fuel. Even though the tank’s pretty heavily damaged and certainly not intended for re-use, we did triple-bag it (just in case of the smell) and put it in the “storage” pile in case we need to reference it in the future.
Next came removing the seat, which appears to be a larger “touring” seat released by BMW as an option after the R90’s manufacture. We’re not sure if we’ll re-use the touring seat or replace it with the sleeker racing-style seat, but we saved it anyway as it’s in pretty good shape. When removing the seat we found the under-seat storage compartment filled with some tools that we know’ll come in handy later: the factory BMW toolkit as well as a number of “modified” hand tools, such as a large socket lathed down to fit in tight spots.
The wiring harness for the R90/6 is located inside the headlight housing, which in this case is covered with a rubber plug because of the Windjammer installation. After removing the rubber we were able to carefully remove the entirety of the wiring harness — such that it is, considering the clunky addition of the trailer wiring kit — and store it for repair later.
And here we have it — the basic R90/6 ready for work. In our next installment we’ll walk through the separation of the rear-wheel and forks, and hopefully soon after that we’ll fabricate a nice engine stand to hold the engine while we tear it down. We’re also beginning research into who can help us straighten the BMW’s frame and forks. Of course we’ll let you know how it’s going.
Check back soon for updates on this and a number of other projects we’ll be bringing into the garage over the next few weeks. And if you have any specific suggestions for projects, don’t hesitate to drop us a line or leave a comment. We’d like to know what, specifically, you’d like to see more of.