2003 ficht 75 prop size

[huntNfish]

Hello,<br />I have just purchased a new 2003 lund explorer 1650 and a evinrude ficht 75.<br />The dealer put on a 13.75X15 prop. I broke the engine in for about 4 hours and started to apply full throttle for short periods of time.<br />I notice that I was only hitting about 34-35mph seen both on GPS and boat speedo. I had adjust the trim up to acheive that speed so I knew that I had adjusted to its best setting. It seemed like once I passed 4700 rpm the speed would not increase as The rpm's would rev up to about 5300 at top end. The boats weight is about 860 lbs. there where 2 adult males (425 lbs) 1 female 110 lbs. and no gear. Does this seem O.K? I would of thought that I should at least go about 40MPH.<br />This was in a river calm day.<br />I had look at evinrudes site and they did a test on a boat the was 995lbs and 2 males 400lbs with 50 lbs of gear and the top speed was 41.8 lbs.<br />I have an aluminum prop, do I need to go to another pitch or is configuration I have about right? Thanks for any advise,<br />KEith

 

[JB]

Re: 2003 ficht 75 prop size

Moving to Outboards.

 

[Bob Kimber]

Re: 2003 ficht 75 prop size

Hi huntNfish,<br /><br />I am no expert, and since I am in Australia I don't know your hull (deep V or not), but I think your WOT rpm with that prop seems low considering the total weight of boat during test. I would suggest talking to dealer about height of the motor on the transom (may be to low) before I start changing props and confirm also that motor is actually achieving full WOT (carb butterflys may not be opening fully), I thought your recommended rpm would be 5500 or more.<br /><br />When I repowered my boat I had to raise the motor one hole above where the dealer installed it to get the anti-ventilation plate or cavitation plate as some people call it to be level with my hull. As an example my boat is a 17ft deep V half cabin, full length Bimini top with a loaded weight of 2,600lb (passengers and gear) using a 17" pitch aluminium prop on a 3cyl 90hp Merc has a speed of 39mph (gps) @ 5,300rpm WOT. My recommended range is 5000 to 5500. <br /><br />With a 15" pitch SS prop same load, motor will WOT at 6000rpm, which is about where I thought yours would be given the much lighter weight and only 15hp less.<br />Bob

 

[Ficht Guy]

Re: 2003 ficht 75 prop size

Huntnfish,<br /><br />I have a 2000 Evinrude Ficht 75hp on a 2001 Starcraft Supersport 16' aluminum deep-v. I have a 13.75 x 15 pitch on my boat which wieghs pretty close to yours. I usually get anywhere from 40 mph with just me down to about 35-37 with 3 people aboard. I also thought my boat should be in the 40's + but everything was checked out by the dealer and everything was fine. The W.O.T. rating for that engine is 5250 so you seem to be getting the full rpms. One thing to realize though is that these are actually heavy engines for their size...almost as much as a 4 stroke. If you have any questions please feel free to email me at truckguygmc23@yahoo.com.