We are proud to say that we are the only manufacturer that offers a wide selection of motors, drives, engines, performance components and gear sets.
In order to get the best forward motion from your engine, whether stock or modified, light or heavy boat, sea level or high altitude you need the correct gear ratio.
Here is the recommended gear set for our short tail models:
14 and 18 Vanguard - 28 to 32 tooth top sprocket and 50 tooth bottom sprocket. (1:1.471 gear ratio) These models have low power and are sensitive to loads. So we gear them according to customer need.
23 Vanguard - 34 tooth top clutch/sprocket and 50 tooth bottom sprocket. (1:1.471 gear ratio) On some models we put a 52 tooth on the bottom for more low end power.
27 Kohler, 29 & 31 Vanguard - 36 top and 50 bottom (1:1.389 ratio). On some models, we put a 52 tooth on the bottom or 34 tooth on top for more low-end power.
35 Vanguard - 38 top and 50 bottom (1:1.316 ratio)
HD 4000 - 38 top and 49 bottom (1:1.289 ratio)
HD 4400 - 38 top and 49 bottom (1:1.289 ratio)
HD 45 Mag - 38 top and 48 bottom (1:1.263 ratio)
HD 5000 - 38 top and 48 bottom (1:1.263 ratio)
HD 6000 - 38 top and 46 bottom (1:1.210 ratio)
HD 7000 - 40 top and 46 bottom (1:1.15 ratio)
Black death 4500 - 38 top 48 bottom (1:1.263)
Black death 5500 - 38 top 46 bottom (1:1.210)
If you hit the rev limiter, go to the 40 top.
Comments: If the customer has a large load, we would decrease the top sprocket by two teeth or add two teeth to the lower sprocket. This causes the engine to spin faster/prop to spin slower for more bottom end power. When the motor is new, it is easy/no expense to change the top sprocket/clutch ratio. Afterwards it is easier and less expensive to just change the lower sprocket size.
Performance Engines: When a customer adds power to his engine we use the above chart to change the gear ratio. Small 100 to 150 rpm changes can be made with one tooth changes such as our 47 and 49 tooth sprockets. Only a few of us use these.
Load: When a customer changes boat and/or increases load we make small adjustments by increasing the size of the lower sprocket by two teeth. Example, increase from 50 to 52 teeth will add 100 to 150 rpm. This can be done on all models except the mini 23 and 27 because the largest lower sprocket that will fit in the outdrive is 50 tooth.
All our lower sprockets are aluminum with an anodized hardened finish. They are interchangeable between Hyper, Sport, Hunter, Lite and Mini models by use of a mounting bushing. Specify when ordering the Hyper busing which has (7/8" drive) or the Sport/Hunter/Lite (25MM) drive shaft size. The cost of replacement sprockets is about $85 plus shipping.