Mercruiser 3.0L 2001 Alpha one leg

[Ribfan]

I brought a boat a few months back a Fairline 21 weekender, 21 foot. with a new mercruiser 3.0L 4 cyl. the engine was never put in the water since the engine change in 2001, as the guy never had the time etc, etc, the guy who sold it to me was a mercruiser dude.<br /><br />Anyway the problem i am having if i have one or two people on board, when i push the throttle as far down as possible. the max revs is about 3200 rpm it takes the boat about 10-20 seconds to plane out of the water, even then the max rpm i can get trimmed up is about 3900 max.<br /><br />With 3 or more people, it wont plane and the max RPM is about 3100-3300.<br /><br />as far as i know the engine has only about 30 hours on it, the prop is a 19" the egine seems to run fine ie no miss fire etc,. the carb was all tested and came back as ok, the whole 30 hours use was from me, this problem has been since day one.<br /><br />Can anyone help me? please <br /><br />thanks for anyhelp

 

[The Marine Doctor]

Re: Mercruiser 3.0L 2001 Alpha one leg

Repower to a V6<br /><br />I know...not the answer you wanted to hear but might be the only solution...Just not enough power.<br /><br />Or try an even lower pitch prop.<br /><br />TMD

 

[akriverrat]

Re: Mercruiser 3.0L 2001 Alpha one leg

says a lot for the durability of that design if you really have been operating a new engine that way with no break in period. over proped or wrong gears in upper. may not be getting enough fuel at higher rpm under load. is choke opening fully? or as the doc said, may just be to small for the boat.

 

[cobra 3.0]

Re: Mercruiser 3.0L 2001 Alpha one leg

I have to agree. That's a small engine for a boat like yours. I have that size on a 16'! I'm using a 17" pitch prop with much success. I don't even think a 17" pitch would do the job for you. Your RPM is way too low. A 15 òr 16" pitch prop will probably do it.<br /><br />Also, you will want to try a hydrofoil device...maybe a Stingray. In the end, the boat will probably plane, but you won't get much speed. I'm guessing 25 miles an hour.

 

[SkippersMinnow]

Re: Mercruiser 3.0L 2001 Alpha one leg

I have the same set up in my 2001 searay 18'BR. Its been fine for me with a load of tennagers to go skiing, even pulls out an adult with three on board. But I would say that the motor is borderline for me in the 18 ft, may be too small for your larger boat. I would say its probably a V6 you will have to go to.