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Brief Summary

Just sprucing up the interior, updating the electronics and maybe adding a new paint job isn’t enough when you are trying to take a classic like the 31 Bertram and breathe new life into her. Richard Mastry of Mastry Engine Center in St. Petersburg, Florida recently took us on a ride down memory lane with one of his passions-- repowering beautiful old Bertrams. He has repowered over 30 of them, so we would call him a pro and since he helped bring Yanmar marine engines into the US, he could also be considered a professional resource for repowering a boat with Yanmar engines. This particular model has been repowered with twin Yanmar 6LPA-STP2s.

Key Features

Key Features of 6LPA-STP2:
  • Compact profile
  • Easy access to maintenance points
  • 24 valve overhead cam 6 cylinder in-line four stroke 4.1 liter
  • 899 lbs per engine
  • Gear reduction starter
  • Two-stage fuel injectors
  • 80 amp alternator
  • Cast stainless mixing elbow for longer life
  • Wet turbo
  • Multiple transmissions available

    **Contact Bertram Yachts for complete model information**
  • Specifications

    Length Overall 30' 7''
    Beam 11' 2''
    Dry Weight 9, 400 lbs. (with fuel)
    Tested Weight N/A
    Draft 2' 7''
    - Draft Up N/A
    - Draft Down N/A
    - Air Draft N/A
    Deadrise/Transom N/A
    Max Headroom 6' 2''
    Bridge Clearance 8' 0''
    Weight Capacity N/A
    Person Capacity N/A
    Fuel Capacity 220 gal.
    Water Capacity 18 gal.
    Length on Trailer N/A
    Height on Trailer N/A
    Trailer Weight N/A
    Total Weight
    (Trailer, Boat, & Engine)

    Prices, features, designs, and equipment are subject to change. Please see your local dealer or visit the builder's website for the latest information available on this boat model.

    Engine Options

    Std. Power Not Available
    Tested Power 2 x 315-hp Yanmar 6LPA-STP2 Diesel
    Opt. Power 2 x 315-hp Yanmar 6LPA-STP2
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    Acceleration Times & Test Conditions

    Time To Plane 5.3 sec.
    0 to 30 8.4 sec.
    Ratio 2:1
    Props Michigan 18 x 25 4 blade broze
    Load 3 pers., Fuel 107 gal., Water 12 gal , min. gear
    Climate Temp: 90 deg., humid: 47%, wind: 5 mph, 10 mph: min chop

    Captain's Report

    Test Result Highlights

    • Top speed for the Bertram 31 (1981) - Yanmar Repower (Not Prod) is 37.4 mph (60.2 kph), burning 29.4 gallons per hour (gph) or 111.28 liters per hour (lph).
    • Best cruise for the Bertram 31 (1981) - Yanmar Repower (Not Prod) is 20.1 mph (32.3 kph), and the boat gets 2.01 miles per gallon (mpg) or 0.85 kilometers per liter (kpl), giving the boat a cruising range of 397 miles (638.91 kilometers).
    • Tested power is 2 x 315-hp Yanmar 6LPA-STP2 Diesel.

    Standard and Optional Features


    Full Warranty Information on this brand coming soon!

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