Mercury Marine's racing outboards

Mercury Marine has long been the acknowledged leader in the production of racing outboards and currently there are six models in its range.

Apart from the SST120/S2000 and XR2, all models are handcrafted and finished by one person at a time (from the bare powerhead castings through to the race-ready product). Sub-assembly personnel build fuel systems, electrical components and accessories, and when mounted on the powerhead each engine is then dynamometer-tested.

On completion of the dyno run, a final check includes removing the spark plugs and inspecting each cylinder bore with a fibre-optic scope.

All models operate on a 32:1 premix using Quicksilver Performance Blend 2-Cycle Outboard Lubricant, and all alternators have regulated outputs.

The F1 is the smallest of three models which operate on race fuel. It develops 280 propshaft horsepower at 9000rpm and utilises the reliable, long-running 60° vee 1998cc powerhead, which is used in the standard Mercury 135 and Optimax 115 models. However, to improve acceleration and allow for higher revs an aluminium flywheel is used.

Designed for freshwater sportsboat race-tunnel hulls and speeds in excess of 100mph (161kmh), the F1 has standard EFI, enabling it to perform as well on high altitude dams as at sea level. There's no need to worry about re-jetting the carbies according to barometric pressure or significant performance loss on warm, humid days the bane of most carburetted engines.

Standard is a 16 amp alternator and a V1 SSM (Super Sport Master) gearcase which has a stepped-up 1:1.07 ratio. The shaft length is 12 inches and the prop a left-hander with exhaust exiting above the gearcase. A hydraulic up/down cylinder, which doubles as the swivel pin for the transom bracket clamp assembly, allows the driver to fine-tune the trim and handling for best performance in varying water-surface conditions. The weight is a mere 125kg, including gearcase.

The carbie version is the SST120/S2000, which develops 200 prop hp at 7500rpm on premium ULP from the same-displacement powerhead and is designed to be a 'training' engine for drivers who eventually want to upgrade to F1 by simply changing powerheads. Again, it has an aluminium flywheel and the same 12-inch shaft is used. Standard are a 16 amp alternator and the 1:1.07 V1 SSM box. The weight is 125kg.

Utilising the proven 2507cc, V-six powerhead used in the standard 175 and 200 and Optimax 135/150 (which, in turn, is a bored-out version of the 1998cc powerhead), the S3000 develops 300 prop hp on race fuel at the same revs and is designed for tunnel hulls. Like its F1 counterpart, the S3000 has hand-ground exhaust ports and 'NiCom'-plated aluminium cylinder bores, which (according to Mercury Marine) provides better heat transfer throughout the cylinder block.

Again, the S3000 has EFI and a 16 amp alternator. The shaft length is 12 inches, but the engine is sold without a standard gearcase. In this form it weighs 125kg.

Again, using the 2507cc powerhead, the 2.5 Drag is designed for both tunnel hulls and freshwater, V-bottom sportsboats. It develops the same output at the same revs on race fuel as the S3000, has EFI and a 16 amp alternator. With a 15-inch shaft and the standard SM (Sport Master) gearcase it weighs 170kg. The SM differs from the V1 SSM in that it takes a right-hand prop and has through-hub exhaust designed to exit around the prop at low revs, enabling the engine to quickly reach its torque band.

One variant of the 2.5 Drag is the 2.5 Offshore Race, which develops 280hp at 8000rpm on premium ULP and is designed for offshore sportsboat race catamarans and V-bottom monos. It has the same powerhead and 1.87:1 SM gearcase, but computer-controlled ignition timing advance is used in conjunction with EFI instead of the standard CDI of its counterpart and the F1 and S3000. It also has a regulated 60 amp alternator and is available in 15 or 20-inch shaft lengths and choice of prop rotation. In 15-inch form it weighs 181kg.

A smaller-displacement variant of the 2.5 Offshore Race is the XR2, which develops 200 prop hp at 7000rpm on premium ULP and is designed for offshore sportsboat V-bottom monos. It displaces 1998cc, has carbies and standard CDI and uses the 32:1 mix. The same 1.87:1 SM box is used and a 16 amp alternator is standard. The shaft length is 15 inches and weight 181kg.

To ensure complete control of these models, Mercury Racing uses 'Zero Effort Controls' which are a stackable, modular unit designed to be used in one to six-lever configurations. Trim tabs, known as 'K-Planes', are also available to help get the boat out-of-the-hole and stabilise it in crosswinds.

All models are available within six to eight weeks of firm order and come with a one-year general warranty and three-year corrosion/perforation coverage. For more on these engines, contact Ken Evans, tel (02) 9821 3600.