Aetna Engineering
Precision digital tachometers, shaft-speed instruments, senders, and sensors for marine and industrial RPM monitoring.
Aetna Engineering, manufactured by Fireboy-Xintex, produces solid-state digital engine and shaft tachometers, mechanical senders, magnetic sensors, and installation accessories. Its Classic Series instruments are permanently calibrated and designed for precise RPM readings, helping operators synchronize engines and find efficient operating speeds.
Products from Aetna Engineering
51 products
Aetna EngineeringAetna 13705 Black Tachometer Trim Ring
3-5/8" Black plastic trim ring for black bezel tachometer.
SKU AET-13705
$7.50MSRP $9.00
Low stock · 2 leftAetna EngineeringAetna 8402R-B-DS Red LED Auto-Dimming Digital Tachometer
Tachometer, round, red LED display with automatic low-light dimming, black anodized aluminum bezel (B) For use on diesel engine.
SKU AET-8402R-B-DS
$310.00MSRP $360.00- Low stock · 2 leftAetna Engineering
Aetna 8402R-B-H-DS Red LED Auto-Dimming Digital Tachometer
Tachometer, round, red LED display with automatic low-light dimming, black anodized aluminum bezel (B) With LCD hour meter, for use on diesel engine.
SKU AET-8402R-B-H-DS
$345.00MSRP $405.00 
Aetna EngineeringAetna 8402R-P-DS Red LED Auto-Dimming Digital Tachometer
Tachometer, round, red LED display with automatic low-light dimming, polished stainless steel bezel (P) For use on diesel engine.
SKU AET-8402R-P-DS
$310.00MSRP $360.00
Aetna EngineeringAetna 8901 Mechanical Tachometer Sender
Sender, mechanically driven, single output, fits most tach drives on diesel engines.
SKU AET-8901
$325.00MSRP $380.00
Aetna EngineeringAetna 8902 Mechanical Tachometer Sender
Sender, mechanically driven, (8901 with dual output, high & reg. voltage output).
SKU AET-8902
$355.00MSRP $415.00
Aetna EngineeringAetna 8905R-B-DS LCD Red-Backlit Digital Tachometer
Tachometer, round, LCD display with red backlight, black anodized aluminum bezel(B) For use on diesel engine.
SKU AET-8905R-B-DS
$325.00MSRP $380.00- Low stock · 2 leftAetna Engineering
Aetna 8905R-B-H-DS LCD Red-Backlit Digital Tachometer
Tachometer, round, LCD display with red backlight, black anodized aluminum bezel (B) With LCD hour meter, for use on diesel engine.
SKU AET-8905R-B-H-DS
$360.00MSRP $420.00 
Aetna EngineeringAetna 8905R-P-H-DS LCD Red-Backlit Digital Tachometer
Tachometer, round, LCD display with red backlight, polished stainless steel bezel (P) With LCD hour meter, for use on diesel engine.
SKU AET-8905R-P-H-DS
$360.00MSRP $420.00
Aetna EngineeringAetna 8910 Flywheel Gear Sensor
Flywheel gear sensor, single output (3/4"- 16 tpi, 2-1/2" long).
SKU AET-8910
$220.00MSRP $255.00
Aetna EngineeringAetna 8922 Flywheel Gear Sensor
Flywheel gear sensor, single output (5/8"- 18 tpi, 4" long).
SKU AET-8922
$240.00MSRP $280.00- Made to orderAetna Engineering
Aetna 8924 Ballast Resistor
24 Volt ballast resistor (drops overall current to 12v dc).
SKU AET-8924
$9.00MSRP $11.00 - Usually ships 3-5 daysAetna Engineering
Aetna 250-3093 Replacement Magnet
Replacement magnets for 8709 magnetic sensor kit.
SKU AET-250-3093
$14.00MSRP $16.00 - Usually ships 3-5 daysAetna Engineering
Aetna 8104 Tachometer Sender Drive Tip
Drive tip, sender, male 0.104" square x 0.187" round.
SKU AET-8104
$42.00MSRP $50.00 
Aetna EngineeringAetna 8152 Tachometer Sender Drive Tip
Drive tip, sender male 0.152" round x 0.187" round.
SKU AET-8152
$42.00MSRP $50.00- Usually ships 3-5 daysAetna Engineering
Aetna 8152-F Tachometer Sender Drive Tip
Drive output for 8901 sender, female, 0.152" round.
SKU AET-8152-F
$42.00MSRP $50.00 
Aetna EngineeringAetna 8187 Tachometer Sender Drive Tip
Drive tip replacement for 8901, male 0.187" round x 0.187" round.
SKU AET-8187
$42.00MSRP $50.00- Usually ships 3-5 daysAetna Engineering
Aetna 8187-D Tachometer Sender Drive Tip
Drive tip for 8901 sender, male 0.187" round x DIN spade.
SKU AET-8187-D
$42.00MSRP $50.00 - Usually ships 3-5 daysAetna Engineering
Aetna 8203 Tachometer Sender Drive Tip
Drive tip, sender, male 0.203" round x 0.187" round.
SKU AET-8203
$42.00MSRP $50.00 
Aetna EngineeringAetna 8402R-B-Dir-DS Red LED Auto-Dimming Digital Tachometer
Tachometer, round, red LED display with automatic low-light dimming, black anodized aluminum bezel (B) direction indicating, for use with SS-2 or SS-3 sensor.
SKU AET-8402R-B-Dir-DS
$435.00MSRP $510.00- Usually ships 3-5 daysAetna Engineering
Aetna 8402R-B-G Red LED Auto-Dimming Digital Tachometer
Tachometer, round, red LED display with automatic low-light dimming, black anodized aluminum bezel (B) For use on gas engine.
SKU AET-8402R-B-G
$310.00MSRP $360.00 - Usually ships 3-5 daysAetna Engineering
Aetna 8402R-B-H-G Red LED Auto-Dimming Digital Tachometer
Tachometer, round, red LED display with automatic low-light dimming, black anodized aluminum bezel (B) With LCD hour meter, for use on gas engine.
SKU AET-8402R-B-H-G
$345.00MSRP $405.00 - Usually ships 3-5 daysAetna Engineering
Aetna 8402R-P-Dir-DS Red LED Auto-Dimming Digital Tachometer
Tachometer, round, red LED , polished stainless steel bezel (P), direction indicating, for use with SS-2 or SS-3 sensor. red LED display with automatic low-light dimming.
SKU AET-8402R-P-Dir-DS
$435.00MSRP $510.00 Aetna 8402R-P-G Red LED Auto-Dimming Digital Tachometer
Tachometer, round, red LED display with automatic low-light dimming, polished stainless steel bezel (P) For use on gas engine.
SKU AET-8402R-P-G
$310.00MSRP $360.00
Choose the right Aetna tachometer system
Start with the display style and application: 8402R models use bright LED readouts, while 8905R models use LCD displays. Match the instrument to a gas engine, diesel engine, or direction-indicating shaft installation, then select the compatible sender, sensor, drive adapter, and wiring accessories.
Accurate RPM monitoring for marine engines and shafts
Aetna Engineering instruments are manufactured by Fireboy-Xintex for precise engine-speed and shaft-speed monitoring. The solid-state designs are permanently calibrated and have no moving display parts to stick or wear out.
- Digital engine and shaft tachometers
- LED and LCD display options
- Mechanical senders and magnetic speed sensors
- Drive adapters, reducers, trim rings, and installation accessories
Frequently asked questions
Who manufactures Aetna Engineering products?
Aetna Engineering products are manufactured by Fireboy-Xintex. Aetna is the instrumentation brand used for its digital tachometers, shaft tachometers, senders, sensors, and related accessories.
What is the difference between Aetna 8402R and 8905R tachometers?
The 8402R Series uses a red LED display, while the 8905R Series uses an LCD display. Both families include models for specific engine, bezel, hour-meter, and direction-indicating applications, so the complete part number matters.
How do I choose a sender or sensor for an Aetna tachometer?
Match the sender or sensor to the tachometer model and the engine or shaft pickup method. Check the full Aetna part number and installation requirements before ordering; contact our technical team if you need help confirming compatibility.
Need a quote on Aetna Engineering gear?
Tell us what you're building. Our team will spec the right kit for your install and send a written quote.
Why buy from us
We carry this brand because it earns its place on the boat.
Stocked for marine builds
We focus on parts that meet the conditions boats see — not just whatever ships fastest.
Engineering review on request
Send a parts list or a layout and we'll check it against your boat before you order.
Direct from our team
Pricing, availability, and product questions all go through the same people who build custom harnesses and panels.