American Turbine AT-309

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Summary

Before Operating Your Jet Boat

Safety and Operating Information

General advice for safe operation and preventing damage to the boat.

Boat Horsepower Capacity

Advice on not overpowering the boat to prevent accidents and damage.

Boaters Responsibilities

Operator's duty for correct and safe operation and occupant safety.

Pre-Operation Inspection

Thrust Bearing Lubrication

Details on lubricating thrust bearings and frequency of maintenance.

Hand Hole Cover Inspection

Check for secure fastening of the hand hole cover before operation.

Steering System Check

Verify nozzle movement with steering wheel operation for safety.

Reverse Shift Control Function

Check reverse bucket positioning in different gear settings.

Throttle Operation

Ensure the throttle operates smoothly during checks.

Transom Seal Integrity

Inspect for leaks at the housing seals to the boat and bowl.

Packing Gland Inspection and Adjustment

How to inspect and adjust packing gland nuts for proper compression.

Weep Hole Inspection (SD-309;SD-312)

Inspect weep hole for mechanical seal condition or debris.

Engine Cooling Connections Check

Check that all engine cooling hose connections are tight.

Operating Procedures and Break-In

Trailer Launching and Retrieval

Procedures for launching and retrieving the boat from a trailer.

Engine Starting and Warm-up

Advice on starting the boat engine and warming it up properly.

Break-In Period Requirements

Importance of break-in period for thrust bearing and seals for longevity.

Handling Practice and Feel

Get acquainted with the jet drive's handling characteristics through practice.

General Maintenance Procedures

Lubrication (Thrust & Bowl Bearings)

Details on lubricating thrust and bowl bearings, including grease types and frequency.

Shaft Packing Adjustment

How to adjust shaft packing for proper compression and prevent leakage.

Reverse Components Inspection

Inspect reverse bucket for proper function and secure attachments.

Steering Cable Checks

Safety check of all steering cable connections on the boat.

Hand Hole Cover Tightness

Periodically check hand hole cover tightness on land.

Lack of Performance Troubleshooting

Diagnose performance issues like pump over-revving due to debris.

Impeller Information and Selection

Impeller Size Considerations

Factors influencing impeller choice: speed, economy, engine life, noise.

Impeller Selection Chart (Models 12-S, 12-TD, AT-309, TJ-309, SD-309, J120-AT)

Chart for selecting impellers based on horsepower and desired RPM.

Impeller Selection Chart (SD-312 Gen 1)

Chart for selecting impellers for SD-312 Gen 1 models.

Impeller Selection Chart (SD-312 Gen 2)

Chart for selecting impellers for SD-312 Gen 2 models.

Safety Precautions

Retrieving Skiers Safely

Recommend shutting off engine when retrieving downed skiers.

Ski Rope Suction Hazard

Avoid ski ropes being sucked into pump; shut off engine for retrieval.

Shallow Water Operation Risks

Caution about rocks and debris in shallow water causing damage.

Braking Effectiveness

Use braking action conservatively due to its effectiveness.

Engine Cooling While Running

Do not operate engine out of water to prevent damage.

Limited Warranty Information

Warranty Coverage and Duration

Covers defects in material and workmanship for 12 months from purchase.

Warranty Claim Process

How to make a warranty claim by returning defective parts.

Exclusions and Limitations

Lists items not covered by warranty, like third-party parts or normal wear.

Product Damage Exclusions

Excludes damage from misuse, neglect, corrosion, improper installation, or exceeding RPM limits.

Liability and State Law Limitations

Limits liability for damages and notes potential state law variations.

Understanding Boat Performance

Self-Service Maintenance Tips

Tips for owners to perform maintenance for good performance and reliability.

Troubleshooting Approach

How to pinpoint problems by dividing the boat into categories: unit, engine, hull.

Tachometer as Key Indicator

The tachometer is key for identifying performance drop-off and engine health.

Hull & External Factors

Problems like overload, balance, drag, or reverse bucket issues affecting performance.

Jet Unit Component Issues

Issues like blockage, impeller wear, or stator vane damage affecting performance.

Air Leaks and Engine Problems

How air leaks and engine issues affect performance and RPM.

Excessive Noise Diagnosis

Common causes of noise like cavitation, worn bearings, or vibration.

Warranty Registration Form

Owner and Boat Information

Fields for owner name, address, boat make, model, and engine details.

Dealer and Sale Details

Fields for dealer name, date of sale, and pre-delivery inspection status.

Signatures and Submission

Owner and dealer signatures required for warranty registration.

This document is an owner's manual for American Turbine jet drives, including models AT-309, TJ-309, SD-309, SD-312, Dominator 12-S & 12-TD, and Legend J120-AT. It provides essential information for the safe operation, maintenance, and understanding of these jet propulsion systems.

Function Description

The American Turbine jet drives are propulsion systems for boats that use a pump to expel a high-velocity jet of water, generating thrust. Unlike propeller-driven boats, jet boats do not have external propellers, making them suitable for shallow water operation and reducing the risk of injury from rotating blades. The system includes an intake adaptor, suction piece, impeller (not explicitly labeled but implied by "pump"), bowl, nozzle housing, nozzle, reverse bucket, and tiller arm for steering.

Important Technical Specifications

The manual includes impeller selection charts for different models, indicating horsepower (H.P.) and corresponding RPM values for various impeller sizes.

For Models 12-S, 12-TD, AT-309, TJ-309, SD-309, & J120-AT (Aluminum Impeller):

Maximum Rating: 400 BHP and 5000 RPM for aluminum impellers.
Impeller Sizes: 9.5, 9.25, AA, A, B, C (9.5" being the largest, C being the smallest).
Horsepower Range: 150 H.P. to 550 H.P.
RPM Range (approximate, varies by H.P. and impeller size):
- 150 H.P.: 2900 RPM (9.5) to 4050 RPM (C)
- 550 H.P.: 4800 RPM (9.5) to 5850 RPM (B) (C is N/A)
Note: Horsepower requirements are at the pump shaft. RPM values may vary depending on how the boat loads the pump.

For Model SD-312 Gen 1 Aluminum & Stainless:

Impeller Sizes: 8.1S, 8.1A, 5.7S, 5.7A, 4.3S, 4.3A.
Horsepower Range: 150 H.P. to 550 H.P.
RPM Range (approximate, varies by H.P. and impeller size):
- 150 H.P.: 3075 RPM (8.1S) to 3800 RPM (4.3A)
- 550 H.P.: 4725 RPM (8.1S) to 5900 RPM (4.3A)
Note: Horsepower requirements are at the pump shaft. RPM values may vary depending on how the boat loads the pump.

For Model SD-312 Gen 2 Stainless:

Impeller Sizes (in KW): 2.4 KW, 2.6 KW, 2.9 KW, 3.3 KW, 4.0 KW, 5.0 KW.
Horsepower Range: 150 H.P. to 550 H.P.
RPM Range (approximate, varies by H.P. and impeller size):
- 150 H.P.: 3600 RPM (2.4 KW) to 2825 RPM (5.0 KW)
- 550 H.P.: 5550 RPM (2.4 KW) to 4350 RPM (5.0 KW)
Note: Horsepower requirements are at the pump shaft. RPM values may vary depending on how the boat loads the pump.

The manual emphasizes that a larger impeller is generally more efficient, requiring less RPM for a given boat speed, leading to better fuel economy, less engine noise, and longer engine life, potentially at the expense of a slight loss in top-end speed (1-2 mph). The jet drive demands a constant load against the engine, preventing lugging as in an overloaded propeller-driven craft.

Usage Features

Steering: Jet boats are highly responsive to steering due to the absence of torque. Tighter turns can be made, but practice at lower speeds is recommended.
No Steering Without Power: A critical safety feature is that jet boats will not steer without power to the jet.
Braking: Jet drives allow for quick braking by pulling the control into reverse. However, shifting into reverse at planing or high speed can result in serious injury, death, or boat damage. Conservative use of braking action is advised.
Reverse Shift Control: The reverse bucket covers the nozzle's discharge opening in full reverse, clears it in full forward, and covers about 3/4 of the opening in neutral. It should have a provision to lock in the forward position.
Shallow Water Operation: Jet drives are suitable for shallow water, but operating in rocky areas can lead to ingestion of small rocks and debris, causing damage to internal parts. Caution is advised in rocky water.
Engine Cooling: The jet drive provides engine cooling. Operating the engine out of water can cause severe damage to both the engine and the jet drive.
Hand Hole Cover: This cover provides access for inspection and maintenance. It should be tightly fastened and generally not removed in the water unless clearly above the waterline (for AT-309, 12-S, & J120-AT models).
Boater's Responsibilities: The operator is responsible for safe operation and should understand the manual. At least one additional person should be instructed in basic operation.
Horsepower Capacity: Do not overpower or overload the boat. Overpowering can lead to loss of control, boat breakup, serious injury, death, or boat damage.

Maintenance Features

Pre-Operation Inspection: A thorough inspection is recommended with the selling dealer before first use, after 10-20 hours, and every three months thereafter.
Thrust Bearing Lubrication: Lubricate every 30 hours or if the boat sits for more than 2 months, using VALVOLINE SYNTHETIC #985, SFR #2522, or equivalent. Do not use wheel bearing grease. About 4-5 pumps are recommended. Lubricate before the first outing in spring.
Bowl Bearing Lubrication: Lubricate at winterization, summarization, and midway through the boating season using the same grease as the thrust bearing. Access is through the nozzle, requiring a long extension on the grease gun. If a Droop Snoot is present, it must be removed.
Packing Gland Inspection (AT-309, TJ-309, 12-S, 2TD, & J120-AT):
- The two packing gland nuts should be snug. If loose, tighten in quarter-turn increments until snug, then back off slightly less than a quarter turn.
- After the first hour of break-in, inspect and adjust if necessary with the boat in water and engine running.
- Excessive tightening can cause heat damage to the shaft; excessive looseness can cause air/water leakage.
SD-309 & SD-312 Weep Hole Inspection: A weep hole indicates the condition of the mechanical seal. Water leakage suggests a failed seal or foreign debris. A blast of compressed air may clear obstructions.
Engine Cooling Connections: Ensure all hose connections are tight.
Transom Seals: Check for leaks at the housing seal to the boat or the housing seal to the bowl.
Reverse Components: Inspect every 30 hours for proper function. The reverse bucket should have no play when the cable is under tension. Ensure the cable attachment to the bucket and tiller arm is secure. Adjustments can be made at the tiller arm's bulkhead fasteners.
Hand Hole Cover: Periodically check for tightness.
Lack of Performance: If the pump over-revs when trying to plane, it's likely due to foreign material (stick, leaf, etc.) in the impeller eye. Always remove the ignition key before placing hands inside the jet drive.
Troubleshooting (Understanding Your Boat):
- Tachometer: The most important instrument for performance monitoring. RPMs should remain consistent regardless of age, loading, or water conditions.
- Normal Maximum RPM (Hull Problem): If RPMs are normal but performance is poor, check for:
  - Overload (too much weight).
  - Balance issues (weight too far aft causing nose high, or too far forward causing plowing).
  - Dragging reverse bucket.
  - Excessive hull drag (rough surface, broken keel strips, "hook" in metal hulls).
- High RPM (Jet Unit Problem): If RPMs are higher than normal with lack of thrust, check for:
  - Blockage (weeds, stones, ski rope, fishing line, plastic bags in intake grate or around pump shaft).
  - Impeller wear (dull leading edges, increased wear-ring clearance from sand pumping).
  - Damaged bowl/stator vanes.
  - Air leaks (faulty gland seal, loose inspection cover) causing the jet unit to "slip."
- Low RPM (Engine Problem): If RPMs are lower than usual, it's almost certainly an engine problem. Check:
  - Throttle opening.
  - Fuel supply and pressure.
  - Air supply to the carburetor (cool air).
  - Ignition system (proper spark).
  - Exhaust system (free flowing, no blockages, excessive water injection).
- Excessive Noise:
  - Cavitation: Sounds like a rattle or loose bolts, indicating the jet unit is starved for water, often due to a blocked intake grate.
  - Moan or Whine: A new or more obvious moan/whine, especially a low-frequency grumble at idle increasing with RPM, suggests a rough/worn/water-damaged thrust bearing.
  - Periodic Vibration: Often at specific RPMs, likely torsional vibration from universal joints on the drive shaft.

The manual also includes a limited warranty section, covering defects in material and workmanship for 12 months from the date of purchase, with specific exclusions for normal wear and tear, misuse, improper installation, racing, and modifications. A warranty registration card is provided, which must be completed and mailed within 15 days of sale to validate the warranty.