Honda Sabre V4 - V4 Engine

V4 Engine

The V45 Sabre was introduced in 1982. It shared its V4 engine design with the Magna and Interceptor. The engines in the Sabre and Magna were so similar to be almost completely interchangeable except for a few fuel and carburation-related differences. The Interceptor engine was angled differently in the frame and had a chain drive instead of shaft, but shared the same 90-degree-V four-cylinder, DOHC configuration.

The V4 engine combined the high-revving power of an in-line four-cylinder with the narrow width of a v-twin. The 90-degree angle of the V also gave the engine perfect primary balance, which helped avoid the vibration problems that plagued many in-line four-cylinder motorcycle engines without the need of heavy solid rubber mounts.

In 1984 import tariffs were changed, causing the V45 engine to be modified. Honda reduced the displacement to 698 cc by destroking the motor from 48.6 mm to 45.4 mm, added a tooth on the clutch gear to compensate for a loss of torque and changed the model name to VF700S. The VF700S models continued for only one more year.

The 750 cc V45 engine produced 82 hp (61 kW) for 1982 models. 86 hp (64 kW) for 1983–1985 models. 76 hp (57 kW) for 700 models. The 1,100 cc "V65" engine, which was introduced in 1983, produced 121 hp (90 kW). Both were slightly detuned throughout the run of the first generation engine to cope with customs and EPA regulations. However, Honda reported the same horsepower figures throughout the whole generation even though the actual dyno-proven, detuned, figures showed up lower than advertised.

The engine's downfall was premature camshaft wear in some early models in both the V45 and V65. In retrospect, the wear was caused by inadequate oil flow to the heads/cams driving for a long time on low engine speeds (under 3,000 rpm) and at cold start /engine warm-up procedure, non-accurate valve adjustment, and insufficient maintenance. But this came too late to save the engine's reputation. Honda itself at first denied there was a problem, then blamed inadequate or incorrect maintenance for the problem. They changed the maintenance interval, and developed and sold a special tool for 'proper' valve-lash adjustment. They eventually made changes to the design and production methods of the engine which eliminated the problem.

But it was too late. The first generation V4 was discredited, and the first V4 revolution failed. While Yamaha (the V-Max) and Suzuki (the Madura) had both responded to the Hondas with V4 engines of their own. Eventually, Suzuki dropped the Madura, and the production of the Yamaha V-Max was continued for over 20 years.