Max Power · Bow thruster

Max Power CT bow thrusters (CT25–CT165)

The CT series are Max Power’s electric tunnel thrusters: a DC motor with power relay and electronic control box sits on a composite drive leg that is filled with oil and sealed for life, needs no anode and must never be opened. The tunnel decides most spare parts: 110 mm for the CT25, 125 mm for the CT35 (one propeller) and CT45 (two), 185 mm for the CT60 (one) and CT80 (two) at 12 or 24 V and for the CT100 (12 V) and CT125 (24 V, now also 48 V), and 250 mm for the CT165 (24 V). Max Power was founded in 1987 in Mandelieu in the south of France, moved its production to Monza, Italy, at the end of 2011 and is now part of the Lalizas group, like Lofrans; the 2004 manuals still sold the same sizes as the ‘Super Power’ series, which Max Power maps one to one to today’s CT models. The retractable Compact Retract and VIP150 share the 185 mm leg and propeller with the CT80 to CT125 but have their own manuals, as do the larger CT225 to CT325. Before ordering, note voltage and serial number and look at how the propeller is held: on the 185 mm propellers Max Power changed from a set screw to a lock nut.

Manuals & documents

The links go to Max Power’s own documents — some as archived copies of pages the maker has since taken down. We host no manuals or drawings.

Wear parts & part numbers

PartOEM numberAlso fitsNote
Propeller350301,2,3—CT25: 110 mm, one propeller, held by a 13 mm nut (10 Nm). Not the CT35/CT45 propeller, although that one used to carry this number too.
Propeller350411,4,3replaces 35030—CT35 (one) and CT45 (two): 125 mm, held by an M8 DIN 985 A4 lock nut, 634969 (13 mm, 10 Nm).
Propeller350401,5,6,3replaces 35031—185 mm, set-screw version (3 mm Allen key, 3 Nm): older CT60 and CT80 and the CT100/CT125 with serial numbers 42250 to 83327; one on the CT60, two on the others. Also on the Compact Retract and VIP150.
Propeller6365767,8,9,1—185 mm, nut version, held by an M12 DIN 985 A4 lock nut (19 mm, 25 Nm): in the current CT60/CT80 manual, on the CT100/CT125 from serial number 83338 and on the CT125 48 V.
Propeller350421,10,3replaces 35032—CT165 (and CT225): 250 mm, two per thruster, each on an M14 DIN 985 A4 lock nut, 634213 (22 mm, 25 Nm). Max Power says to set the blades neither horizontal nor directly opposite each other.
Propeller drive pin636080 · 312058 · 312053 · 3120592,4,7,10,11—One per propeller, between propeller shaft and hub: 636080 CT25 · 312058 CT35, CT45 · 312053 CT60 to CT125 · 312059 CT165.
Drive leg (thruster)63609812,2,13—CT25: 110 mm, one propeller; comes with fixing screws, leg gasket, propeller pin and nut.
Drive leg (thruster)31531812,4,13replaces MP028000—CT35: 125 mm, one propeller; comes with the two DIN 912 M6 × 40 A4 screws, leg gasket, propeller pin and nut.
Drive leg (thruster)31037612,4,13replaces MP028002—CT45: 125 mm, two propellers; comes with screws, leg gasket, propeller pin and nut, as for the CT35.
Drive leg (thruster)3503412,7,13replaces MP058100—CT60: 185 mm, one propeller, mounted off-centre so the propeller sits in the middle of the tunnel; comes with the DIN 912 M8 × 55 A4 screws, leg gasket, propeller pin and M12 lock nut.
Drive leg (thruster)3503512,7,8,13replaces MP088100—CT80, CT100 and CT125 (also Compact Retract and VIP150): 185 mm, two propellers; comes with screws, leg gasket and propeller pins, in the current manuals also the two M12 lock nuts.
Drive leg (thruster)31532112,10,13replaces MP118100—CT165 and CT225: 250 mm, two propellers; comes with the DIN 933 M10 × 65 A4 screws, leg gasket, propeller pins and M14 lock nuts.
Drive leg gasket310255 · 310254 · 3102524,7,10,11—Gasket between leg and tunnel: 310255 CT25, CT35, CT45 · 310254 CT60 to CT125 · 310252 CT165. Coat both sides thinly with silicone grease or a hydrocarbon-resistant sealant, never graphite grease, and keep the screw holes free of it.
Motor636059 · 312863 · 6362592,4,14—12 V motors: 636059 CT25 · 312863 CT35 · 636259 CT45.
Motor312865 · 312866 · 636260 · 6362617,14—CT60 12 V 312865, 24 V 312866 · CT80 12 V 636260, 24 V 636261. Each with heat sensor; brushes and springs are listed separately.
Motor312869 · 312871 · 636662 · 3128708,9,15,14,10—CT100 12 V 312869 · CT125 24 V 312871 · CT125 48 V 636662 · CT165 24 V 312870. The VIP150 retractable uses the same 12 and 24 V motors as the CT100 and CT125.
Motor brushes636077 · 3127024—CT35, CT45: motors from 2007 take four brushes 636077, earlier ones eight 312702; springs 310383.
Motor brushes312702 · 3127037—CT60, CT80: eight per motor, 312702 for 12 V, 312703 for 24 V; springs 310383.
Motor brushes312704 · 312705 · 3127038,10—Eight per motor: CT100 312704 and CT125 24 V 312705 (springs 310384) · CT165 312703 (springs 310385).
Relay312921 · 312920 · 3129192,4,7,8,16—12 V power relays: 312921 CT25, CT35, CT45 (complete relay assembly 315325 for CT35/CT45) · 312920 CT60, CT80 (assembly 315326) · 312919 CT100 (assembly 315328).
Relay312923 · 3129227,8,10,16—24 V power relays: 312923 CT60, CT80 (complete assembly 315327) · 312922 CT125 and CT165 (assemblies 315329 and 315331).
Control unit31531017,7,8replaces MPOP5701—Electronic thruster controller for all of Max Power’s electric tunnel thrusters (sold as the post-2014 unit); every current CT manual lists it.
Overheat sensor311363 · 311365 · 3113662,4,7,8,10—Heat sensor in the motor that triggers alarm and shutdown: 311363 CT25, CT35, CT45, CT100, CT125 · 311365 CT60, CT80 · 311366 CT165.
Flexible coupling6360822,18—CT25 coupling between motor and leg; the CT25 also uses motor key 631310 and drive-leg key 636072.
Flexible coupling315304 · 3153054,7,11—Spring and pivot coupling kit between motor and leg: 315304 CT35, CT45 · 315305 CT60, CT80. Grease the motor shaft and drive pin before fitting the motor.
Flexible coupling630487 · 633743 · 6337468,5,10,11—CT100, CT125: motor-side hub 630487 (key 631312), PG56 rubber insert 633743 (red on older units, black on current ones) and leg-side hub 633746, set with 2 mm (±1 mm) play. The CT165 uses two 630487 hubs with the same insert.
Fuse3502119,2,4,7,20,21replaces OPTI3114—125 A T1 fuse: CT25, CT35, CT45 and the 24 V CT60 and CT80; the 2025 catalogue also lists it for the CT125 48 V, whose manual asks for a 125 A ANL fuse. Max Power sizes the fuse to the cable, not to the motor current, and only covers installations with original parts.
Fuse35019 · 3502019,7,8,20—T1 fuses: 160 A 35019 for the CT60 12 V · 200 A 35020 for the CT80 12 V and the CT125 24 V.
Fuse35022 · 3502719,8,10,20—315 A T2 fuse 35022 for the CT100 · 250 A T1 fuse 35027 for the CT165.
Fuse holder / fuse base35017 · 35018 · 31288219,2,7,8,10,21,22—Holder T1 35017 for the CT25 to CT80 and the 24 V CT125, holder T2 35018 for the CT100; for the CT165 the manual and product page give T1, the 2025 catalogue and the fuse page T2. The CT125 48 V uses the ANL holder 636347. 312882 is the extraction handle for T1 and T2.
Fuse636342 · 636343 · 636344 · 636345 · 63634621,23,24,7,10,9—Max Power ANL fuses, in holder 636347: 150 A 636342 CT25 · 175 A 636343 CT35, CT45 and CT60/CT80 24 V · 225 A 636344 CT60/CT80 12 V and CT125 24 V · 325 A 636345 CT165 · 400 A 636346 CT100. The CT125 48 V takes a 125 A ANL fuse.
Electric battery isolator318400 · 31840125,7—Electric battery isolator in the motor’s positive cable, switched by the control box: 318400 12 V (up to the CT100), 318401 24 V (up to the CT165). Recommended, not mandatory; without it, seal off the control box’s two grey wires and isolate the motor circuit with the manual battery switch after use.
Control panel / joystick318200 · 318202 · 318204 · 7589221,26,27,28,7—Max Power panels for all tunnel thrusters: touch panel 318200 (grey 318201), joystick 318202 (grey 318203), double joystick for bow and stern 318204 (grey 318205), and the newer black two-direction joystick 75892 (IP67). Swapping an old joystick for the 75892 needs a new cutout (75 × 109 mm instead of 65 × 65 mm). All plug into the control box’s 6-wire cable; if a panel stays dark, check that connector first.
Cable31278121—Control cable, 6 × 0.5 mm², between panel and control box for all CT tunnel thrusters (25 m reel); the Y connector 634004 runs two panels in parallel on one thruster.
Joystick rubber boot31293029—Black rubber boot for the single (318202) and double (318204) joystick panels, per Jimmy Green.

Numbers checked against the sources below on 23 October 2026. Always confirm against your serial number and exact type before ordering.

Service intervals

TaskInterval
BatteryRegularly: check charge and condition, since voltage drop is the most frequent cause of rapid relay wear7,4
Electrical connectionsRegularly: check batteries, connections and power cables, and make sure every terminal is tight7
Motor brushesRegularly: take the motor off and blow the brush dust out with compressed air; the 2004 manual says to replace brushes worn by more than 70 %7,30
PropellerWhenever the boat is out of the water: clear fishing line, plastic bags and the like from the propellers; keep propellers and tunnel clean and the leg and propellers antifouled over a primer7
GreaseYearly, after cleaning the leg: coat the drive shafts and the stainless covers of the oil seals with silicone grease before refitting the propellers; no aggressive solvents7,8

From section 18 ‘Maintenance’ of Max Power’s current manuals, which is the same for the CT25 to CT165. Apart from the yearly greasing, Max Power sets no hours or months; the composite leg needs no oil change and no anode and must not be opened. Max Power wants the work done by qualified personnel, with the control and power circuits isolated first.

Specifications

TypeElectric (DC) tunnel thruster: motor with power relay and electronic control box on a composite drive leg that is oil-filled, sealed for life and needs no anode; case-hardened spiro-conical gears, line shields. Mono = one propeller (CT25, CT35, CT60), duo = two (CT45, CT80, CT100, CT125, CT165)31,7,12
ModelsProduct codes: CT25 636061 · CT35 42529 · CT45 317603 · CT60 42530 (12 V) / 42531 (24 V) · CT80 42532 (12 V) / 42533 (24 V) · CT100 42534 · CT125 42535 (24 V) / 636660 (48 V) · CT165 317557. Not on this page: the larger CT225, CT300 and CT325, the ignition-protected CT-IP versions, stern pods and the retractable Compact Retract and VIP21,32
Tunnel110 mm CT25 · 125 mm CT35, CT45 · 185 mm CT60, CT80, CT100, CT125 · 250 mm CT165; tunnel wall 4–5 mm (110 and 125 mm), 6–7 mm (185 mm), 7–8 mm (250 mm). The rated thrust assumes a tunnel no longer than twice its diameter21,31
ThrustAt 10.75 / 12 V (12 V units) or 22 / 24 V (24 V units): CT25 26 / 30 kgf · CT35 30 / 35 · CT45 40 / 45 · CT60 63 / 70 (12 V), 65 / 71 (24 V) · CT80 75 / 80 (12 V), 83 / 89 (24 V) · CT100 96 / 105 · CT125 115 / 122 (24 V; the 48 V version the same at 45.6 / 48 V) · CT165 165 / 185 kgf. Measured with the tunnel one diameter below the waterline, ±6 %21,31,33
MotorCT25 1.8 kW · CT35 2.69 kW · CT45 3.23 kW · CT60 4.35 kW (12 V) / 4.4 kW (24 V) · CT80 4.79 / 5.28 kW · CT100 7.1 kW · CT125 8.58 kW (24 and 48 V) · CT165 11.88 kW21,31,33
Voltage12 V: CT25, CT35, CT45, CT100 · 12 or 24 V: CT60, CT80 · 24 V: CT165 · CT125: 24 V, or 48 V in the newer version. Designed to run at 10.75 V (12 V units), 22 V (24 V) and 45.6 V (48 V); a higher voltage gives more thrust and current but a shorter duty cycle21,34
Current drawMaximum current in Max Power’s fuse tables: CT25, CT35, CT45 250 A · CT60 330 A (12 V) / 180 A (24 V) · CT80 360 A / 200 A · CT100 550 A · CT125 330 A (24 V), 210 A (48 V) · CT165 560 A2,4,7,8,9,10
WeightCT25 7 kg · CT35 9.6 kg · CT45 9.65 kg · CT60 14.7 / 14.8 kg (12 / 24 V) · CT80 15 / 15.1 kg · CT100 24 kg · CT125 24 kg (48 V: 24.3 kg) · CT165 36 kg21,31,33
Suitable boat lengthMax Power’s ranges: CT25 up to 7.3 m (24 ft) · CT35 17–31 ft · CT45 20–34 ft · CT60 25–39 ft · CT80 28–46 ft · CT100 32–51 ft · CT125 35–60 ft · CT165 40–65 ft; the lower end for heavy boats with high windage, the upper end for light ones21,18
Installation depthTop of the tunnel below the waterline, minimum / ideal: CT25 82 / 110 mm · CT35, CT45 94 / 125 mm · CT60 to CT125 139 / 185 mm · CT165 188 / 250 mm. As far forward as possible; the propellers must not stick out of the tunnel2,4,7,8,10
Max. running timeS2 rating of 2–3 minutes (CT165: 2.5 minutes), less at high ambient temperature. A thermal switch in the motor sets off the alarm; 10 seconds of thrust later the control box shuts down until the motor has cooled7,10
Breaker / fuseMax Power ceramic / ANL fuse: CT25 125 / 150 A · CT35, CT45 125 / 175 A · CT60 160 / 225 A (12 V), 125 / 175 A (24 V) · CT80 200 / 225 A (12 V), 125 / 175 A (24 V) · CT100 315 / 400 A · CT125 200 / 225 A (24 V), ANL 125 A (48 V) · CT165 250 / 325 A. The control box needs its own 8 A fuse or breaker2,4,7,8,9,10
Power cable sizeFor a total cable length (plus and minus) up to 5 / 10 / 15 / 20 m: CT25, CT35, CT45 50 / 70 / 120 / 150 mm² · CT60, CT80 12 V 70 / 95 / 150 / 185 mm², 24 V 25 / 50 / 70 / 95 mm² · CT100 95 / 150 / 240 / 300 mm² · CT125 (24 and 48 V) 50 / 70 / 95 / 120 mm² · CT165 50 / 95 / 120 / 150 mm²; PVC insulation rated 105 °C or more, M8 terminals up to the CT80, M10 on the CT1652,4,7,8,9,10
BatteryMaintenance-free starting-type batteries with a high CCA rating, for example 12 V 55 Ah / 800 CCA; for the CT60/CT80 Max Power reckons with about 50 Ah for 10 minutes of use a day. Charge them from the engine alternator and a charger, with a dedicated bank as close to the thruster as possible. Designed for lead-acid, AGM or gel; with lithium batteries the current must not exceed the thruster’s maximum7,35
ControlElectronic control box 315310 with a Max Power touch panel or joystick on a 6-wire cable: childproof switch-on, beeps and a green LED, a delay when reversing direction, overheat alarm, switches itself off after 10 minutes unused (older CT100/CT125 manual and data sheets: 30 minutes) and controls the optional electric battery isolator7,5,36,17
Tightening torquesLeg screws: CT25, CT35, CT45 12 Nm (2 × 6 mm, 5 mm Allen key) · CT60 to CT125 25 Nm (2 × 8 mm, 5.5 mm Allen key) · CT165 35 Nm (2 × 10 mm, 6 mm Allen key). Motor support screws: 20 Nm (CT25 to CT45), 30 Nm (CT60, CT80), 40 Nm (CT100 to CT165). Propeller: 13 mm nut 10 Nm (CT25 to CT45), M12 lock nut 25 Nm or set screw 3 Nm (185 mm), 22 mm nut 25 Nm (CT165)2,4,7,5,8,10
Warranty2 years from purchase, transferable to the next owner; 3 years if registered with Max Power within 3 months of purchase. Commercial use: 6 months. In year 2, wear of motor, oil seals and relay contacts is excluded7
PredecessorSuper Power series (2004 manuals), mapped by Max Power to today’s models: Super Power 35 → CT35, 45 → CT45, SE55/60 → CT60, SE65/80 → CT80, SE90/100 → CT100, SE110/125 → CT125, SE165 → CT165. The Super Power 80 to 225 were also offered with a bronze ‘Classic’ leg, which needs oil and an anode37,30,38

Good to know

  • The composite drive leg is filled with oil and sealed for life: there is no oil to change and no anode to replace, and opening it, even partly, voids the warranty. Max Power’s answer to worn leg seals is an exchange leg, so a leaking leg means a new leg (35035 on the CT80, CT100 and CT125), not a seal kit.7,12
  • There are two 185 mm propellers: 35040 is held by a set screw (3 mm Allen key, 3 Nm), 636576 by an M12 lock nut (19 mm, 25 Nm). On the CT100 and CT125 the change came at serial number 83338, and the current CT60/CT80 manual lists only the nut version, so look at your hub before ordering. And beware of the old number 35030: it used to be the 125 mm propeller of the CT35 and CT45 (now 35041) and today is the 110 mm propeller of the CT25.1,5,8,7
  • According to Max Power, voltage drop is the most frequent cause of rapid relay wear, and it wears the brushes too. With the boat in the water, batteries charged and the engine running, the motor terminals should show about 10.5 V (12 V units) or 22 V (24 V) while thrusting; if they don’t, check battery size and charge, cable sizes and every connection, including the battery switch and the fuse.7
  • Max Power designs its standard on/off thrusters, the CT range included, for lead-acid, AGM or gel batteries and warns that Li-ion or LiFePO4 batteries quickly damage motor, relay, control box and transmission unless the system is specified for them; the manuals add that the current drawn from lithium batteries must not exceed the thruster’s maximum. Only Max Power’s ECO proportional range is designed for lithium.35,7
  • A CT is made for short bursts: 2–3 minutes at a time at most (S2 rating), less when it is hot around the motor. When the motor overheats, the panel beeps and the LED flashes; after 10 more seconds of thrust the control box shuts down, and the thruster cannot be switched on again until the motor has cooled. Never run it with the boat out of the water: Max Power says that can damage the motor.7
  • Before ordering brushes or a motor for a CT35 or CT45, check its age: motors from before 2007 take eight brushes (312702), later ones four (636077). If the motor runs but the boat doesn’t move, Max Power’s checklist starts with the propellers and the drive from motor to leg: a spring-and-pivot coupling on the CT35 to CT80, and on the CT100, CT125 and CT165 two hubs with a PG56 rubber insert, which should leave 2 mm (±1 mm) of play.4,8,10,39

Videos & how-tos

Links to YouTube, nothing embedded. The maker’s own channel comes first; the rest are channels we found clear and correct for this model.

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Sources

  1. max-power.com/products/max-power-accessories/propeller
  2. max-power.com/download/01KKGH22XA83RMTZ4RTW7QKF7H
  3. jimmygreen.com/product/max-power-propellers/
  4. max-power.com/download/01KKGH1ZZM06774GEN82JRFGC5
  5. max-power.com/download/01KKGH2009GWJVEZFMVM8ZDFSA
  6. max-power.com/products/retractable-thrusters/electric-retractable-thruster-compact-retract
  7. max-power.com/download/01KKGH2000H5FZ179KCPM6ZY7Y
  8. max-power.com/download/01KKGH200P8MQ9GV1VQ1SY39AX
  9. max-power.com/download/01KKGH22T3KAF42AQWB3HK3NPN
  10. max-power.com/download/01KKGH200Y1B2MQKX30C77GZVH
  11. jimmygreen.com/product/max-power-bow-thruster-replacement-parts/
  12. max-power.com/products/max-power-accessories/leg
  13. jimmygreen.com/product/max-power-thruster-drive-legs/
  14. jimmygreen.com/product/max-power-bow-thruster-replacement-motors/
  15. max-power.com/products/retractable-thrusters/electric-retractable-thruster-vip-150-electr…
  16. jimmygreen.com/product/max-power-relay-only/
  17. max-power.com/products/max-power-accessories/control-boxes
  18. max-power.com/products/tunnel-thrusters/electric-tunnel-thruster-ct-25
  19. max-power.com/products/max-power-accessories/fuse
  20. jimmygreen.com/product/max-power-fuses/
  21. max-power.com/catalogue
  22. max-power.com/products/tunnel-thrusters/electric-tunnel-thruster-ct-165
  23. max-power.com/products/max-power-accessories/max-power-anl-fuse-for-thruster
  24. max-power.com/products/max-power-accessories/maxpower-anl-fuse-holder
  25. max-power.com/products/max-power-accessories/electric-battery-isolator
  26. max-power.com/products/max-power-accessories/touch-panel
  27. max-power.com/products/max-power-accessories/joystick-simple
  28. max-power.com/products/max-power-accessories/max-power-joystick-2-directions-for-tunnels-…
  29. jimmygreen.com/product/max-power-replacement-rubber-joystick-cover/
  30. web.archive.org/web/20061026231811/http://www.max-power.com/product/download/documents/ma…
  31. max-power.com/products/tunnel-thrusters/electric-tunnel-thruster-ct-80
  32. max-power.com/products/tunnel-thrusters/electric-tunnel-thrusters
  33. max-power.com/download/01KKGH22TQX59C20BVWNJFF00D
  34. max-power.com/products/tunnel-thrusters/electric-tunnel-thruster-ct-125
  35. max-power.com/faq
  36. max-power.com/download/01KKGH207AR59W4YA3BA6KKA0F
  37. max-power.com/retired-models
  38. web.archive.org/web/20061026232534/http://www.max-power.com/product/download/documents/ma…
  39. max-power.com/download/01KKGH22MF20YTZHW0NGEXQYGD

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