Performance of Grady White 228G

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  • Performance of Grady White 228G

    I have a 2009 Grady White 228G with a 250 Yamaha 4S. I am 6100 rpms at WOT but only 38 mph. I am also having a difficult time keeping it on plane below 4000 rpms. The prop is a 15.5 x 17 factory prop, which is what the factory used in their performance tests. I had it checked by a prop shop over the winter and it is within spec. The bottom is clean and I just checked the outboard bracket for water and it has none. The motor is mounted in the second hole which is the same as other 228's that I have looked at. So now I have narrowed it down to the prop. I'm not as concerned with top speed, I more concerned with cruising speed. I would like to see around 30 mph at 4000 rpms.
    Any suggestions.


  • #2
    I'd go Powertech OFS4 in 17 pitch.
    Lot of sternlift, and much better traction.
    Right now, you have a lot of slip, 23%
    OFS would bring your RPM down a little, and bring your cruise speed up.
    Also give a lot of overall lift.

    Ken Reeves
    [email protected]


    • #3
      Thanks Ken.


      • #4
        I have a 1999 Grady 228G with a 1999 Yamaha 2 stroke ox 66 225 hp mounted in the second hole. It will do 41 mph with no problem. I think something else is going on with yours.The sweet spot for cruising is 3600-3800 rpm which is around 30-32 mph. The prop is the 15 1/4 x 17 stainless that it came with. Are you carrying around alot of excess weight ? No water in the bilge? I can get up on plane at around 19-20 mph. I had the prop checked and the hub tested and all was good.I think you should be seeing better performance.
        Last edited by mjm1957; 06-06-2019, 06:46 AM.