sea ray getttin on speed

pfitz128

Cadet
Joined
Jul 11, 2011
Messages
9
I need some help, I have a 2003 24 ft sea ray sundancer with a 5.0 mercrusier. last weekend I loaded up the boat with people and gear and set out to enjoy a day on the water, but when I set out I could not get above 12.5-13 knots, no matter how I trimmed the boat it just would not go, yesterday I took the boat out again and had 5 people on (I had eight before) and again it just would not go, so we decided to just head up the river and stop at a resturant and get some lunch, after about 15 minutes the boat began to pick up speed and after we had lunch we headed back and every thing worked like a champ, it did this last year a couple of times, and I changed the fuel/water seporater and it did not seem to help. it is almost like something is clogging and some how works its way through, but on ocassion the problem returns, the boat never spits and sputters, it starts fine and even when I go full throttle it seems like it wants to go but it just stalls around 12-13 knots,
 

Brentathon

Petty Officer 1st Class
Joined
Dec 29, 2009
Messages
385
Re: sea ray getttin on speed

"...after about 15 minutes the boat began to pick up speed..."??? Does that mean you were full-throttling for 15 minutes?
If you can't get up on plane at full throttle in under a minute, I would back-off the throttle, as you may be loading the engine quite high.
I have a 23ft mid-cabin w/ 5.7, and with 8 people my boat struggles a bit to get on plane.....ESPECIALLY if there's nobody sitting forward.
Drive should always be trimmed FULL DOWN to get on plane, and putting load forward helps a lot.

A good test: with light load (1 or 2 people), boat NEEDS to reach the engine's spec'd RPM range at full throttle. If it doesn't, then you definitely have a problem.
 

nikogto

Seaman
Joined
Apr 25, 2010
Messages
56
Re: sea ray getttin on speed

Replace the spark plugs on it and try it then. If that fixes it, replace cap and rotor also.
 

pfitz128

Cadet
Joined
Jul 11, 2011
Messages
9
Re: sea ray getttin on speed

yes I agree about the weight, but I was at full throttle and doing about 12-13 knts and I could tell that the engine began to pick up, I tried it several timesmost of the day, after it picked up and began acting normal, I stopped for lunch, i left the dock and had 2 people on the aft seat, 2 people on the aft facing seat, and I hit the throttle and it picked up speed and got on plane rather quickly
 

pfitz128

Cadet
Joined
Jul 11, 2011
Messages
9
Re: sea ray getttin on speed

I will say that this comes and goes it did it to me to or three times last year but randomly,
 

ma454mike

Cadet
Joined
Feb 5, 2011
Messages
10
Re: sea ray getttin on speed

It sounds like it could be bad fuel. Maybe a bit of water in the fuel you purchased of condensation in your tank.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,465
Re: sea ray getttin on speed

yes I agree about the weight, but I was at full throttle and doing about 12-13 knts and I could tell that the engine began to pick up, I tried it several timesmost of the day, after it picked up and began acting normal, I stopped for lunch, i left the dock and had 2 people on the aft seat, 2 people on the aft facing seat, and I hit the throttle and it picked up speed and got on plane rather quickly

Ayuh,... Welcome Aboard,...

When was the last time she was given a Full Tune Up, 'n Complete Service,..??
 

Fedds

Seaman Apprentice
Joined
Jul 10, 2007
Messages
48
Re: sea ray getttin on speed

My 2002-2003 5.0L MPI did this EXACT same thing. Pull the distributor cap the next time it happens and check for moisture...this model is notorious for it and the cap will corrode. I have to replace mine every few years. Do a search on my name in the advanced search mode and you will find a number of my threads on this problem, the GM NAPA part numbers, and th service bulletin on this issue (I hope this is your issue, it's an easy fix.)
 
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