Chuck, the speedo will error differently as you change the setup. For instance, raising the motor might get you less pressure into the speedo hole, which will lower the speedos version of the speed, even though the true speed might increase.If youre having holeshot problems, whats your RPM? It could be that the Tempest could have some vent plugs added/removed. My 1999 225 Opti didnt hit the powerband until about 3000 RPMS. you could spin at 2000 for as long as you wanted and not go much of anywhere. If youre running under 3000 RPMs on holeshot, remove one of those plastic plugs from the prop. If it doesnt improve, remove another one. If, on the other hand, your RPMs are at 5000+ and youre just not getting any “bite” with the prop, you need to add a plug. Normally, those props come stock with all holes having large plugs. Usually thats a good starting point. However, you might need to put in medium or smaller plugs if youre just sitting there spinning the prop and not getting any forward movement.
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