boat not going wot?

S

samedley

Seaman Apprentice
Joined
Jul 4, 2012
Messages
38
i just bought a 20ft vip with a omc 5.7l,cobra and 19p prop.i got it out on the water yesterday and it doesnt seem to be getting full throttle. it only goes up to 3700-3800 rpm@41mph. i was playing with the trim too. you have to push the handle down pretty for for it to go into gear and get throttle.
 
Boomyal

Boomyal

Supreme Mariner
Joined
Aug 16, 2003
Messages
12,072
Re: boat not going wot?

Things to consider: When you fully depress the throttle lever, is the carb actually opening all the way? Is the hull clean? You did not say what year the boat was. Is it possible that things are waterlogged below deck? That could add tons of weight
 
N

NeedaBiggerBoat

Seaman Apprentice
Joined
May 28, 2011
Messages
46
Re: boat not going wot?

I was just reading your other post where the motor was overheated and the impeller was thrashed, your RPM should be around 4400 and 4600 RPM at WOT I would check the timing with a timing light to see where its at and check your points. While you are in there a compression check on all the cylinders couldn't hurt either that alone can give you loads of information.
 
S

samedley

Seaman Apprentice
Joined
Jul 4, 2012
Messages
38
Re: boat not going wot?

The throttle could open up a little more. The throttle blades aren't vertical. Next time I have it out I'm going to have my buddy drive while I open them up all the way by hand. What should timing be at idleing and how much should it advance to when reved? The boat is an 1988. What should compression be? The Carb is dirty so I am going to spray cleaner in it. What should fuel pressure be idleing and wot?
 
Bondo

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,448
Re: boat not going wot?

What should timing be at idleing and how much should it advance to when reved?
Click to expand...

Ayuh,.... Hard to say, as you've haven't really ID'ed the motor, other than it's a 350....
So,.... I'd guess 'tween 6?Btc, to 10?Btc...
Fully advanced, 'bout 30? Btc to 36?Btc..
What should compression be?
Click to expand...

Over 100 psi, 'n under 200 psi...
The Carb is dirty so I am going to spray cleaner in it.
Click to expand...

That's Irrelevant,.. Where ya Can't see, Inside is what needs Cleanin'.... That's why it's called Rebuildin' a carb...
What should fuel pressure be idleing and wot?
Click to expand...

4 to 6 psi....

4 to 6 psi....
 
S

samedley

Seaman Apprentice
Joined
Jul 4, 2012
Messages
38
Re: boat not going wot?

All I know is it says 5.7l 4v. I think its 200hp. How can I tell what Carb is on it?
 
Boomyal

Boomyal

Supreme Mariner
Joined
Aug 16, 2003
Messages
12,072
Re: boat not going wot?

samedley said:
All I know is it says 5.7l 4v. I think its 200hp. How can I tell what Carb is on it?
Click to expand...

Check the manual. If someone changed it, it is anyone's guess. You could post a picture of it.
 
N

NeedaBiggerBoat

Seaman Apprentice
Joined
May 28, 2011
Messages
46
Re: boat not going wot?

samedley said:
All I know is it says 5.7l 4v. I think its 200hp. How can I tell what Carb is on it?
Click to expand...

If it is a Rochester Quadra Jet there might be a Rochester stamp on the port side of it. If I were to guess I'd say that its either that or a Holley. Like I said it would just be a guess look for the stamp on the side.
 
You must log in or register to reply here.
Top