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Re-Powering a 31 Stamas express

Discussion in 'Tenders & Dinghies' started by George., Mar 3, 2016.

  1. George.

    George. New Member

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    I am thinking of re-powering a 1999 31 Stamas express with twin 250 offshore yamaha's or twin 250 mercury verado's. I currently have twin xo66 Saltwater ll 2 strokes

    Any thought's on the best choice.
  2. Capt J

    Capt J Senior Member

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    Yamaha 4 strokes. Your boat is already set up for them. The Yamaha's seem to be more durable. I manage several boats with Verado's, lots of issues with all of the bolt on parts....power steering pumps, superchargers, lower units, trim cylinders, steering cylinders, isolator boots, etc. etc......
  3. George.

    George. New Member

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    Thanks Capt, for your reply, I do see more Yamaha's around here in the Keys than Merc's however, you-tube has some video's out there talking down Yam's and talking up the Merc's. So its got me a bit confused.
  4. YachtForums

    YachtForums Administrator

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    This isn't the best forum for this question. Seek opinions on the Hull Truth. That said the OX66 is a robust, reliable straight forward 2 stroke, albeit a bit thirsty. But you already know this. CaptJ's opinions on the Verados mirror the experience of others. To me, it doesn't make sense to repower. Rebuild! It's hard to justify the fuel savings based on the cost of new 4-strokes, not to mention recovering your investment if you sell at a later date.

    As Yamaha has increased output to compete in the market, they are pushing the threshold of reliability. I would look at the smaller displacement 4-strokes from Yamaha, such as the 225 or 250. They have been pretty solid motors, but a little more expensive to repair than Mercs.

    And finally, i'm moving this thread to the tender forum. The technical forum isn't the right place for outboards.
  5. Capt J

    Capt J Senior Member

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    Well the 2 stroke smell of the OX's gets a little bit old. A friend of mine repowered his 28' Mako. It had 225 hp Yamaha 4 strokes, he put the new 200hp Yamaha 4 strokes and they're lighter, fuel efficient, and just as fast as the heavier 225's he replaced. I have always been a Mercury man until I started managing/maintaining boats with Verado's and Optimax's.

    The 300hp 4 stroke Yamaha's are bulletproof also. The 350's have some inherent issues. There is something to be said for having new motors that start when you turn the key. Yeah you can rebuild the old ones, but then the wiring, accessories, castings and other stuff are still old
  6. Pascal

    Pascal Senior Member

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    The differences between older two strokes and new 4 stroke is huge in noise, smoke, vibration. Well worth it

    As to which engine. Almost every yacht tender, club or harbor launch, fishing boat in the islands has yamahas not Mercs. I personally believe that if Merc wasn't part of Brunswick group and imposed on brands like Boston Whaler and the likes they would have been out of business a long time ago
  7. RT46

    RT46 Senior Member

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    George,

    good luck with your project.

    Besides brand, performance and weight, one thing to consider is that the repower you are describing could be in the $50k area.

    NADA value of a 1999 31 Stamus is in the 25-30k range.

    I know no boat is an investment. Money spend on a boat, does not always increase its value proportionately.

    You might be able to find a boat with new power for less than you would have wrapped up in your boat.

    The Hull Truth is place I would go for outboard information.

    I also see that some of the YF heavy hitters have commented.
    They are very knowledgeable and I'm not surprised that they have good information to offer.

    I personally know very little about outboard engines.
    I do own them, but they are more of an after thought or an accessory for the tender or for my bay boat.

    I do have a 135 Mercury Optimax on a 22 Chawk.
    Its the engine that was on the boat when I bought it.
    This engine is used and abused 12 months a year.
    I was ice breaking with the Chawk a few weeks ago.

    My 135 Opti is extremely fuel efficient and has well over 1000 hours.
    The oil alarm sometimes sounds when its really cold out before the engine is warmed up.
    The only negative I can think of is that my Opti is loud compared to modern 4 strokes.
    If your OBs are on a bracket the noise might not be as much of an issue.

    If I were considering an outboard repower I would also look at Suzuki and Tohatsu.
    A lot of the OB commercial and hard core recreational fisherman repower with those packages.

    Good luck.
    Last edited: Mar 4, 2016