Mercury 2.5 race

Discussion in 'Performance Outboard Motors' started by David B, Sep 21, 2017.

  1. David B

    David B Active Member

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    Does anyone know much about these motors. It came factory with a 3.0 liter mid and lower unit. What is the hp and max rpm and what do they weight. Would this work on a xb2002
     
  2. RiverRat71

    RiverRat71 Active Member

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    2.5XS? I have a 2005 2.5XS made by Merc Racing on my GS. It is listed as 225HP & weighs 450lb. It is an Optimax engine with max rpm of 6800. Not sure if 6800 is the soft limit. I was told that these motors were only made in 05 but were quite strong & actually dyno'ed around 240. Mine runs well & feels really strong in mid range. I am confident it will eventually push my rig well into the 90's (still learning).The only drawback as far as I see it is the extra weight from having the 3.0 mid & lower. RR
     
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  3. David B

    David B Active Member

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    Do u think this would work on a xb2002
     
  4. David B

    David B Active Member

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    Yes its a 2.5 xs
     
  5. RiverRat71

    RiverRat71 Active Member

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    I would think the XB02 would be considerably faster than a GS with the 2.5XS but I don't know if it exceeds the recommended weight limit that Allison specs for the XB. Maybe someone with more knowledge will weigh in. RR
     
  6. dubmoney

    dubmoney Active Member

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    based upon the reading I have done everyday for the last 6 years. And my experience setting up my own Allison. I think Darris Allison would want the lightest engine possible on his boats. The xb02 was and is predominately rigged with a 2.5 mercury. The 2005 200xs is slightly heavier, and my cause Darris to issue caution. That being said there are people who have run substantially heavier motors and will report good results. in my very humble and limited experience and I think a 2005 200xs would be just fine on a xb2002. I would run it tune it and work on set-up and would bet that it would achieve every thing you ever wanted without any draw backs.
     
  7. David B

    David B Active Member

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    I have been looking a motor weights and from what I see its only 40 pounds heavier than a 280 with a 20 inch offshore. I was hoping to hear if someone has tried this set up. Its not the 200xs its the 2.5 xs race with 3.0 mid and 3.0 sportsmaster 450# .For a xb 2002 thanks
     
  8. pkstv

    pkstv Active Member

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    IMG_2075.PNG Call Allison and ask ! Here is what's posted !
     
  9. msethsmile

    msethsmile Funny Guy

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    Put a 2.5xs on a 2.5 mid/lower?
     
  10. David B

    David B Active Member

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    I think the crank is splined for 3 liter. Don't matter anyway it's a non ratcheting gear case.
     
  11. Darth VMAX

    Darth VMAX Well-Known Member

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    I wouldn't hesitate at all to run a 2.5xs on my Xb2002.

    Where did you find one? They are super rare as 2005 was their only year. Merc killed it way too quickly
     
  12. David B

    David B Active Member

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    A guy at my buddies boat shop has one that he might sell. It has 30 hours on fresh rebuild. Real clean. I thought you could not use a non ratcheting gear case. Or I would have to change it?
     
  13. Dave Hensley

    Dave Hensley Well-Known Member Supporting Member

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    I don't think the weight is an issue period. The issue is the 3 liter gearcase. It is larger and will provide more stern lift on an XB2002. I don't think you could bolt a 2.5 set up on a 2.5XS and expect the boat to handle the same way. The 6800 rpm limit is strange for a 2.5. My sources say the 2.5 Optis are limited due to piston concerns.
     
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  14. RiverRat71

    RiverRat71 Active Member

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    So the same would apply to my GS? I have been told that props blue printed for Allisons are built with more stern lift. With that being said, should that be reconsidered if running the 3 liter lower? Mine has been coned by JC as well. RR
     
  15. Bobalouie

    Bobalouie Active Member

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    I thought they were limited due to the compressor, but I may be wrong.
     
  16. Dave Hensley

    Dave Hensley Well-Known Member Supporting Member

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    I thought they were limited due to the compressor, but I may be wrong.[/QUOTE]

    That too but the gen 2 200XS ROS in SST trim has an 8000 rpm limiter and runs a compressor. The pistons, according to someone a lot smarter than me, are not reliable at that rpm for very long.
     
  17. Dave Hensley

    Dave Hensley Well-Known Member Supporting Member

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    The pencil roll provides stern lift. Stern lift is what gets you in trouble. Real easy to get trim happy when the boat feels like it is flattening out.
     

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