WOT for first time - 5300 RPMs - HELP!!

rhinohorn

Cadet
Joined
May 22, 2004
Messages
23
10 hours on my break-in and tried WOT yeterday. Hit 5300 RPMs and top speed of about 45 (on speedo). A little background:<br />2004 Larson LXi 210<br />260 HP Merc/Alpha 1<br />21 pitch prop<br />I was expecting to land somewhere in the 4400 to 4800 area, but flew right past those RPMs! What is going on? I thought a 21 prop was the factory, conservitive, do-all prop for this boat/engine combo. Maybe I have a "secret" 350 HP Merc!! Any ideas floating around out there? Thanks
 

ThomWV

Senior Chief Petty Officer
Joined
Dec 19, 2003
Messages
701
Re: WOT for first time - 5300 RPMs - HELP!!

OK, What's the problem?
 

LubeDude

Admiral
Joined
Oct 8, 2003
Messages
6,945
Re: WOT for first time - 5300 RPMs - HELP!!

Try a 23 Pitch prop in aluminum if that is what you are running now, or a 21-22P Stainless steel.<br /><br />Should give you a little more top end, and get your RPMs down some.
 

mellowyellow

Vice Admiral
Joined
Jun 8, 2002
Messages
5,327
Re: WOT for first time - 5300 RPMs - HELP!!

I think 5300 is over reccomended RPM's...
 

rhinohorn

Cadet
Joined
May 22, 2004
Messages
23
Re: WOT for first time - 5300 RPMs - HELP!!

5300 RPMs is WAY over the recommended range! Hence the high rev alarm. I always thought I would reprop...like next year after my break-in was complete and I had put the boat through the tests. I wasn't expecting a new boat to come from the factory set up to run danderously high. I can just hear Merc now, "Diagnostics show that your boat was propped wrong and that it hit 5300 RPMs. This is well out of our recommended operating range and therfore voids all warranties!"<br />Is this normal on new, family-oriented boats? Does the factory supply the prop or is it installed by the dealer?<br />Rhino
 

gspig

Chief Petty Officer
Joined
Jul 7, 2004
Messages
409
Re: WOT for first time - 5300 RPMs - HELP!!

Why should you pay for a new prop? If the boat is under warantee, let someone know. Get the problem noted on paper, see if the dealer will reprop.
 

mellowyellow

Vice Admiral
Joined
Jun 8, 2002
Messages
5,327
Re: WOT for first time - 5300 RPMs - HELP!!

dealer noramally props the boat...<br />have you asked them? maybe a faulty tach. even?
 

ThomWV

Senior Chief Petty Officer
Joined
Dec 19, 2003
Messages
701
Re: WOT for first time - 5300 RPMs - HELP!!

I still wouldn't be in all that much of a hurry to be switching props just yet. How many people did you have with you, was there a couple of hundred pounds of the stuff people carry in boats aboard, how about a couple of hundred pounds of ice? Was it full of fuel or with a light tank at the time?<br /><br />Just about any dealer will do prop exchanges until you get it right, so I wouldn't worry about that, other than I'd call them up and tell they that they could be expecting you. But then, before I broke out the adjustable wrench, I'd load that boat up and take it for another spin, put it into a headsea too. See how it acts then.<br /><br />I can tell you that I'd rather be low on pitcth than high on pitch any day. It will allow you to hold on plane at a lower speed, it will allow the boat to fight a head sea at a lower speed without falling flat on its nose too. One will give you a bunch better accelleration and all you have to do in return use a little eye-hand coordination when you watch that tach. I'd much rather have the advantages you get from to low a pitch than a couple of more miles per hour on the top end and besides that, using the lower pitch prop will be much easier on your engine and drivetrain, and over time that always pays off.<br /><br />Thom
 

LubeDude

Admiral
Joined
Oct 8, 2003
Messages
6,945
Re: WOT for first time - 5300 RPMs - HELP!!

ThomWV:<br /><br />So I suppose you have 456 gears in you car also???<br /><br />4,000 RPM at 60 MPH!!!<br /><br />Same thing, great lowend power, no economy and engine turns more RPM at the same speed, hence, less engine life.
 

Boomyal

Supreme Mariner
Joined
Aug 16, 2003
Messages
12,072
Re: WOT for first time - 5300 RPMs - HELP!!

Hey lubedude. Been missin ya over in DC. We be havin lots of fun. Drop in and say hi sometime! :D
 

ThomWV

Senior Chief Petty Officer
Joined
Dec 19, 2003
Messages
701
Re: WOT for first time - 5300 RPMs - HELP!!

Yep, more milage on the pistons, rings, and cylinder walls but much lower combustion pressures, so take your pick as to which one does more to promote engine life. I'll opt for the lower combustion pressures myself. Everyone to their own opnion though.<br /><br />Thom
 

JasonJ

Rear Admiral
Joined
Aug 20, 2001
Messages
4,163
Re: WOT for first time - 5300 RPMs - HELP!!

I have to agree with Thom on this one. I know I could go up in pitch on my rig, but I like knowing I can still achieve near peak rpms with 4 adults and gear. I just stay out of the stupid lever when I am by myself and the load is light. I am not in a big enough hurry to benefit from whatever speed increase I may get from a pitch increase. If I wanna go faster, I just slide that lever forward and keep and eye on that tach...
 

LubeDude

Admiral
Joined
Oct 8, 2003
Messages
6,945
Re: WOT for first time - 5300 RPMs - HELP!!

There is a point where I have to agree also, but I think he is a bit passed what I would live with.<br /><br />I use a high Five on my 150 Merc on my Bass Boat in a 25P, 5,700-5,800 RPM. I can get about 3-4 MPH more with a four blade 27P at about 5,300 RPM. I like the performance of the High Five, so thats what I have on it.
 

salty87

Commander
Joined
Aug 12, 2003
Messages
2,327
Re: WOT for first time - 5300 RPMs - HELP!!

if you plan on pulling skiers or anything, the lower pitch will come in handy there too. something else to try out next time on the water.
 

broark01

Cadet
Joined
Jul 1, 2004
Messages
29
Re: WOT for first time - 5300 RPMs - HELP!!

Are you sure your tach is set up correctly? Some boats have tachs that are configured for 4, 6 or 8 cylinders. The reason I ask is that I would have expected the engine to sart cutting out due to rev limiter.
 

jmc830

Cadet
Joined
Jun 23, 2004
Messages
18
Re: WOT for first time - 5300 RPMs - HELP!!

i just bought a 4 winns 214 funship with a 5.0 mpi 260 hp just reached my break in guess what? my wot is also about 5300 rpms at 48 mph like someone else sed get 4 adults on and see what happens
 
D

DJ

Guest
Re: WOT for first time - 5300 RPMs - HELP!!

Agree with ThomWV.<br /><br />The dealer probably set it up so he wouldn't get a complaint of: "too slow out of the hole with 16 kids, four dogs, mother in law and ten ice chests on board".<br /><br />Boats NEVER lose weight, they only gain it. <br /><br />Just because it will over rev doesn't mean that the opeator has to let it.
 
D

DJ

Guest
Re: WOT for first time - 5300 RPMs - HELP!!

Agree with ThomWV.<br /><br />Boats never lose weight, they only gain it.<br /><br />There is an overspeed failsafe, it's called the "operator".
 

rhinohorn

Cadet
Joined
May 22, 2004
Messages
23
Re: WOT for first time - 5300 RPMs - HELP!!

Okay all you helpful, opinionated boaters!<br /><br />My boat had a "normal" load. Family of four, full tank of fuel, cooler, etc. Sure, I'll have heavier loads at times, as well as lighter loads. Tach was also set for 8 cylinders. I called my dealer and told him what was going on. He said that was unacceptable and he is going to ship (two hours away) me a 23 pitch to try out. He believes that I should have no problem getting the boat into the correct operating range without loosing a very respectable hole shot. He said we'll work together until we reach that combination.<br /><br />I'll report on the performance of the 23 when I get it on the water. Thanks for all the insight and your opinions about this problem.<br /><br />Rhino
 

Boatist

Rear Admiral
Joined
Apr 22, 2002
Messages
4,552
Re: WOT for first time - 5300 RPMs - HELP!!

I get the prop that put you in the Proper WOT RPM range probaply a 25 inch for 4500. You get better fuel mileage, higher top speed, and lower rpms at a nice curseing speed. If you are going to pull and lot of heavy skiers or borders then a 23 pitch is a good choice. Boats do gain weight over the years as we add extra gear but your motor may still gain power as it get broke in and the rings seal.<br /><br />I run my car in over drive most of the time doing 65 at 2200 RPMS not 2 gear doing 4400 rpms or 3rd doing 3300 RPMS.
 
Top