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MerCruiser Repower

Example project on a Riviera M400
M400 Water Testing.jpg

What is a MerCruiser repower?

Many customers either own a boat that they love or are looking to buy a second hand boat where the engines have reached an age or condition where it is more cost effective to replace the engine package than carry out major repairs and maintenance. A repower is where we remove the existing engine (and in some cases the transom assembly and drive) and replace them with new.

The benefits of a repower include

  • More power and increased performance

  • More cost effective than repairs or buying a new boat

  • Including the latest fuel injection or digital technology

  • Increased reliability

  • Less time spent on maintenance and repairs

  • Manufacturer's warranty

Example - repowering a Riviera M400

As a very popular boat through the mid 2000's the Riviera M400 has a well-designed hull and a timeles style. We selected this boat to repower as a demonstration package and so we could document the process. 

Boat Specifications

2006 Riviera M400
LOA: 12.30m
LWL: 12.17m
Beam: 4.13m
Draft: 1.08m
Fuel: 1,100L
Water: 500L
Weight: 7,900kg
Engines: MerCruiser 496 DTS with Bravo 3 drives

Replacement Engines: MerCruiser 8.2L HO with Bravo 3 X Drives

Freight & Inspections

A suitable boat was located in Sydney, following a hull survey the settlement was completed and the boat was freighted to our workshop located within The Boat Works at Coomera on the Gold Coast. The freight cost including a pilot vehicle was about $6,500.

Engine package selection 

It was decided to replace the 496 engines with over 1000 hours on the clock with 8.2L HO packages. The HO engines have 430HP each which was a considerable increase from the old engines. The package also included new trim pumps, transom assemblies and Bravo 3 X Drives with 1.81:1 ratio. Opting for complete packages is the most cost effective option as it includes all engine related components. 

Work commences

The first job is to remove the old drives, engines, and transom assemblies. In this case we also removed many of the engine room components so the boat could be brought to a better than new condition. This allowed us to re-paint the engine bay, install all new plumbing and through hull fittings, replace the hot water system, batteries, blowers, and overhaul the black water tank and associated components. The genset was also removed for major repairs. Whilst it is not often necessary to have works completed on so many engine bay components, we carried out the above work as we wanted to ensure the area was in a presentable condition for future inspections and for the engines to look and perform their best. It is also often best to replace items like the hot water system as they are difficult to replace once the engines are installed and have a limited lifespan.

Other work on the boat

One of the benefits of boat works is we have a plethora of on site trades that you can liasise with to work on your vessel while it being repowered. The M400 had the following work completed:

  • New clears and covers

  • New carpet

  • New upholstry

  • New anchor chain

  • Anchor winch overhaul

  • New marine BBQ

  • Engine intake and lower chrome covers re-finished

  • Internal leather cleaned

  • New tender and outboard

  • Hurley davit installed on swim platform

  • LED light replacement (interior)

  • LED navigation light replacement

  • Hull polish and detail

Dash upgrades

We re-deisgned the dash and ordered new replacement panels for a factory look finish. We opted for a Simrad MFD sounder/plotter as it works with Mercury and has an inbuilt Mercury screen available when connected. The existing system link digital gauges were retained. Much of the Mercury harnesses were re-used (but with new key switches, lanyards, etc). The final installed items were:

  • System link analogue look digital gauges for engines

  • VesselView 4 colour screen for engines

  • Simrad touch Go 12"

  • Raymarine VHF

  • Fusion RA70N (linked to Simrad)

Launch time

Usually a repower can be completed in 1-2 weeks. The M400 took sometime longer due to all the additional works and trades involve. Once the boat had new antifoul paint applied it was launched using the Sealift at The Boat Works directly into the Coomera River. All new systems are checked and the boat peformed above expectations with a maximum speed of just over 40 knots. Once handed over, the engines are due for a 3 month (or 20 hour) inspection and then annual maintenance (or every 100 hours whichever first).

Inspections & Demonstrations

Inspections are available by appointment, please contact us. Current pricing can also be found here.

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