1998 225 - Top Speed?

[boatingnyc]

So I recently purchased a 1998 205 Aquasport in great shape with a 225 Saltwater series merc (Carbs) with only about 200 hours. I headed out with a buddy of mine the other night with about 40 gallons of gas. We topped out around 46mph at 5800 rpms. Then this weekend, had 6 people on board and about 60 gallons of gas. During WOT I couldn't get it above 4700 rmps and a top speed of about 38 mph. I used my gps and fishfinder to ensure the speed was accurate. Does this sound right? How come under load the RPMs would not increase? I have been reading that this boat is tested from the factory at about 50mph with a 200hp. Thanks for your help!

 

[robalofish]

Re: 1998 225 - Top Speed?

Check your (boats) weight & trim.<br /><br />2 people = 300 lb (assume your skinny)<br />40gal Fuel = 280 ( 7lb per gal I think is more like 7.5lb)<br />5800 RPM <br /><br />VS<br /><br />6 people = 900 lb <br />60 gal fuel = 420 lbs<br />Probably some coolers etc.<br />4800 RPM ----<br /><br /><br />Most definitely should turn slower - you have 750 more pounds of weight.<br /><br /><br />Take 4 of the people out and check again. 6 People is a lot for a 20' boat. I'm assuming from the 205 number.

 

[boatingnyc]

Re: 1998 225 - Top Speed?

Thanks for the reply. The boat is rated for 8 people / 1850lbs. I use to own a 215 robalo with a 200 merc on it and never remember the engine not being able to get up to WOT RPM numbers with a full load of people. I understand the boat will be much slower under a full load but why won't the engine turn at WOT. Thanks...

 

[KCLOST]

Re: 1998 225 - Top Speed?

It probably won't unless it is propped properly for that load... Bass boat guy's will prop the boat so it runs at max rpm rated for the motor with little or no load. We want maximum speed, normally a higher pitch prop is the result as long as it doesn't sacrifice the hole shot....<br /><br />While pleasure boaters/skiers will prop it so you can still reach close or near the recommended WOT rpm while under the extra load during normal operation. This requires a lower pitch prop....