Description

A modern 4-hole injector is generally an improvement over the original single-hole Bosch injectors fitted to the BMW R850 and R1100 because it atomizes the fuel much better.

The main advantages are:

• Finer fuel atomization – Four smaller spray streams create much smaller fuel droplets, allowing the fuel to mix more evenly with the incoming air.
• Smoother idle – Better combustion at low engine speeds often results in a more stable idle.
• Improved throttle response – The engine reacts more quickly and smoothly when opening the throttle, especially from low RPM.
• Cleaner combustion – More complete burning of the fuel can reduce carbon deposits and exhaust emissions.
• Reduced surging – Many Oilhead owners report less of the characteristic light-throttle surging that early R850/R1100 models are known for.
• Potentially better fuel economy – If the injectors have the correct flow rate and the engine is in good tune, fuel consumption may improve slightly.

Will it increase horsepower?

Not significantly. On an otherwise stock R850/R1100, don’t expect more than 0–2 hp. The noticeable improvements are in:

• smoother running,
• better drivability,
• cleaner cold starts,
• and improved throttle response.