Roostertails and engine height

[Jim@KSC]

Folks -<br /><br />I drove a 1998 18' Eagle flats boat (not war eagle and not the Western Eagle skiff) with a 150 EFI Merc last weekend.<br /><br />I played with the trim above 40 MPH to find a ventilation point. I never got there.<br /><br />The boat was sending back around a 50 foot roostertail ten feet or so in the air.<br /><br />Wouldn't that mean raising the engine at least two holes?<br /><br />Should I pick up some top end?<br /><br />And just how do I find the sweet spot?<br /><br />If it passes the mechanic's test, I will buy it tomorrow.<br /><br />TIA!

 

[snapperbait]

Re: Roostertails and engine height

I can't remember if'n that boat had a tunnel or recess near the transom or not.. Anyway, If the engine reaches it's suggested WOT rpm and is'nt over-reving or venting, and if the boat is riding light with the bow up just a little and not wanting to porpous or do anything funny, I'd leave it alone... <br /><br />Roostertails are'nt necessarily the sign of a bad thing...

 

[Jim@KSC]

Re: Roostertails and engine height

Snapperbait -<br /><br />WOT is a bit low; 5100 vs. 5600. No tunnel, but an 12"+/- recess. WOT is also 51 MPH GPS.<br /><br />I had this engine trimmed about 2 seconds up from tucked. No porposing to notice, but the bow took a while to settle after going over rollers.<br /><br />What surprised me was the trim up it could stand without an indication of ventilation. That, coupled with the roostertail suggested (my darned engineering logic, not experience) the engine was too low.<br /><br />Is this logic flawed?<br /><br />I may add Bob's mechanical jack plate to compensate for the difference between flats running and skiing/tubing, which would give me a chance to play.