dominator jetting
 

i have a 32 ft formula with twin 540s. My carbs are way off. It wont idle and I ran out of fuel at top end. I spun 30 inch bravo 4 blade 4500 or so and ran 75 on gps. But at 4800 i ran out of fuel . I could feeel it. . Any jett recomendations and fuel pump size ?

Re: dominator jetting
 

You will have to tell us if they are new/used? stock/modified? or? 2 circuit or 3?
4150's 850 cfm plus would have been a better choice. Dominators very seldom work right out of the box. The additional 10 or so horsepower you may get is generally not worth the aggravation, testing and cost.

Re: dominator jetting
 

BOATMAN
If you give us the carb list numb on the carb and the intake your using I might be able to point you in the right direction.A bit of cam info will also be helpfull. Sincerely Laz Mesa

Re: dominator jetting
 

I would suggest getting the carbs Blueprinted & flowed by a reputable shop like Dean Nickerson's or ChuckNuytten.com or Pro-systems.com. It will be perfect when you get it back- jetting & everything.

Both are highly reputable and comparable in price. Chuck is turning mine around in two days!! Check out the website.

Re: dominator jetting
 

My cam is 632 lift 245 duration 9.1 compression. Big brodix single plane intakes . 2 circuit metering on the carb . I sent it to a dyno shop and he didnt know what he was doing . VA speed !!! better stay away !

Re: dominator jetting
 

i had a n 850 and the boat ran so lean i could only get 44o hp I put the dominators in and I jumped to 575

Re: dominator jetting
 

It sounds like it might not just be a carb problem.Your fuel system in your boat can have a supply problem.If you want to run dominators, then run 3 circuits.

Re: dominator jetting
 

When you say you run out of fuel. Do you run fuel pressure gauges at the
carbs you should have 6-8 psi at the carbs WOT. My last set of 540,s I had 9377 dominators with dart intakes. I had to replace the pickups in the fuel tanks. I run a Claysmith mechanical with a return style regulator back to the tank. all fuel system should be no less then 1/2 id including pickups valves and filters. A simple test would be to remove the supply at the carb. Have someone else start the engine and time how long it takes to fill a one gallon container. It should be a steady stream and fill it in 25 seconds or less should support approx 700hp. Also make sure your fuel tank vent is 5/8inch.

The fuel system above and test is per engine.

Make sure you do the above test with two people and keep a Fire exstinguisher near by.
Gerry

Re: dominator jetting
 

I have already purchased the 2 curcuit carbs. I just checked my jetts. It had 97 all the way around. A couple friends of mine run 540 s and run 86 all the way around. So I changed to 86,s and it idled pretty good in the drive way. But I am nervous about top end . I think 97,s was very excessive dont ya,ll? I dont want to detinate !~!!

Re: dominator jetting
 

Changing the main jets will have very little if not any effect at idle.

What # is stamped on the top of the carb? Then I can tell you what was in there from the factory. If your over ten sizes from that somethings wrong.

Are you reading plugs? NGK.s I find are the easiest to read.

How do you know your getting enough fuel to the carb?
This is so often overlooked!!! Read my other post and verify you have enough
fuel. Formulas have small pickups in the tank!!

Did I mention checking the fuel supply???
Dont jet just beacuse other 540,s are running them.
All engines are different.