BMW K75

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Produced from 1985-1995, the BMW K75 was a successful entry-level sport touring motorcycle. When it was introduced, the K75 was BMW's cheapest motorcycle. It was a sporty bike - accelerating from 0-60mph in 4.6 seconds for a top speed of 124 mph.

Contents 1 Engine and Transmission 2 Model Designations 3 Issues 4 Resources

[edit] Engine and Transmission

All K75 models share the same drivetrain. They are powered by a 740cc in-line three-cylinder, Bosch fuel injected, engine. The US EPA specific engine produces a claimed 68HP at the crank while all others produce a claimed 75HP at the crank. The K75 utilizes a five-speed transmission and a shaft-driven final drive. The engine used by the K75 is often described as "bulletproof," indicating that it is quite reliable..

[edit] Model Designations

Available unfaired as the K75, bezeled headlight with touring bags, only in the US as the K75T, with a small handlebar mounted 'cockpit' fairing K75C, Sports fixed fairing and lower bars on the K75S, and the full faired Tourer K75RT. S and RT versions have a rear disc brake and 17 inch rear wheels whereas the others have a single leading shoe drum brake and 18 inch rear wheels. A stiffer, "anti-dive" front suspension was added to the S model.

ENGINE: Probably the best part of this bike is the engine. Air and liquid cooled, inline, fuel injected three cylinder on its side. One K75, "Old Smokey," is said to have 340,000 miles on it. The fuel injection has never had an issue either.

COST: Prices vary significantly between the faired (rt) versions of the K75 and the naked versions (s,t,c). Low price ranges are in the $2500-3000 range depending on miles and condition, and can go up to $6000 for a late model RT with low miles, ABS, and Good condition.

[edit] Issues

There are a few problems in the various versions of these motorcycles after a while

INSTRUMENT CLUSTER: Multiple problems exist.

1) The instrument cluster can be damaged by excessive heat. In places such as the southwest of the USA, the plastic can warp causing the lenses to crack, or bending the needles so that they drag or stop altogether.

2) The LCD clock within the instrument cluster can lose segments of its display over time.

3) There is no fuel gauge, just a low fuel light. There is a third party fuel accessory called the fuel plus[1] that replaces the clock and hooks up to the fuel injection computer to act as many things, including a clock, fuel gauge, and trip meter.

RADIATOR FAN: The bearing in the radiator fan can seize after some time. It is unusual for the bearing to fail before 60,000 miles, but after that, failure is likely.

SHAFT DRIVE: The clutch, and final drive splines must be maintained. People argue about intervals at which these should be checked and greased, it varies from every 6000 miles to every 20000 miles. The final drive splines are very easy to get to, so I check those every other oil change. However, the clutch splines are difficult to repair.

SMOKE: Early models of the K75 did not have pinned piston rings. If the rings were rotated with the split on the low side of the engine and the bike was put on its side stand, it would suck oil into the chamber. This caused an embarrassing puff of smoke when you started the bike up. They pinned these rings on 89 and later models, some have found them on earlier models too. No problem occurs when the bike is kept on the center stand.

[edit] Resources

BMW dealers will charge you an arm and a leg for parts and service on any of their motorcycles. It is economical, easy and fun to work on your own bike, especially the K75. There is an active KBMW technical group [2] on yahoo groups. Several members have been there and active for many years and are absolute experts.

The internet BMW riders association ibmwr, has Ktech articles [3] which address some of the most common maintenance, repair issues.

There was some erronious information on this page that has been edited (1-10-2007). I will attempt to enlist the help of those on the yahoo kbmw list to ensure its accuracy and completeness.