Are all Alpha One Gen 2 lower units the same?
All Alpha I’s Lower Unit (not the Pre Alpha with the lift ring/or the pre-load nipple on top of the shaft) are interchangeable. The difference in the gear ratio will be in the Upper Unit. Alpha I Gen II not interchangeable. Meaning a Alpha I upper unit and a Alpha I Gen II lower unit,put together.
How do you tell the gear ratio on a Mercruiser outdrive?
Look on the port side of the upper housing for a serial number,around the vent plug area, under the decal maybe. For the gear ratio you may have to take the upper gears out and count the teeth.
What is the difference between Mercruiser Alpha 1 and Gen 2?
The Alpha Gen II upper and lower housings are fastened together with two through bolts on either side of the drive along with the front and rear bolts, while the Gen 1 drives use one stud visible on either side. Alpha Ones have two studs under the ventilation plate just above the prop.
Are alpha one outdrives interchangeable?
The Alpha One® and Gen II, which are tradenames of MerCruiser®, have a dominant position in the marketplace. The outdrives offered by SEI are fully compatible and interchangeable with MerCruiser® outdrives. Eliminating the middleman reduces SEI’s costs and these savings are passed on to the customer.
How much gear oil does a MerCruiser Alpha one take?
| Brand | Model | Oz./Qts. |
|---|---|---|
| Mercury/Mariner | 225/250/275/300 Verado | 28.7 |
| MerCruiser | Alpha One Gen II | 1.22 US Quarts |
| MerCruiser | Alpha One Gen II | 2.0 US Quarts |
| MerCruiser | Alpha One Gen II | 1.75 US Quarts |
How do you calculate lower unit gear ratio?
The lower unit Gear Ratio and its importance
- Gear ratio (or reduction ratio) is expressed by the number of crankshaft revolutions for one revolution of the propeller.
- The higher (numerically) the gear ratio is the slower the speed of the propeller shaft gets and thus the less the number of propeller’s revolutions is.
How much horsepower can an alpha one handle?
300HP
The Alpha drives are rated for up to 300HP. Not really sure of max torque but probably less than 300 ft/lb. Some people have success using the Alpha drives with higher HP & torque by avoiding quick holeshots and taking it easy on the throttle. Our warranty does not cover applications over 300HP.