Rodrigo Alvarez

Tinkering as a way of life

Category: BMW K75

K75 Restoration: Bike rebuild

Once all the parts were ready to be assembled, I managed to trick a Gonzalo (The same Gonzalo from the kite foil) to help me carry the assembled engine and gearbox from a fourth floor to the garage. Frankly, I started the day thinking the bike wouldn’t start. There could be a thousand other things

K75 Restoration: Engine Rebuild & Final drive maintenance

Taking advantage of the christmas holidays I’ve been working hard on the engine. Having the head removed, it makes sense to check the state of other components, such as the piston rings, connecting rods and bore tolerances. I should replace the big-end conrod bearing shells, which are worn but have not reached their service limit,

K75 Restoration: Valve Job

After careful disassembly, the problem has become more obvious (if possible). The valves themselves, have their stems in tolerance (Inlet: 6.960 – 6.975 mm ;Exhaust: 6.945 – 6.960mm), but the problem relies with the mating surface of the seats. I used the optical measuring machine at ICAI to take a few reference points to compare,

K75 Restoration: Engine diagnosis

Last time I wrote I knew that the engine didn’t start, but lets focus on the good things; The electrical system seems ok, ignition and fuel pump look also alright, and I haven’t seen any obvious leak. Since then, I’ve also taken the time to check the rear spline and it seems it’s in top

K75 Restoration: New endevour

For the last few years I’ve wanted to restore a classic motorcycle. I’ve been looking around on second hand sites but it is hard to find reasonable prices in Spain. You can’t expect to pay less than 2k€ for a larger than 500cc motorbike and even in that case, the state of the engine can’t