More advise?

[NescherMonty17]

EPIC MEMORIAL DAY WEEKEND @ UTE.    Saw the sickest jet boat throwing a mind blowing roostertail that just engulfed the entire cove with "lake mist". It was turbo charged, and topped 101 mph on less than admirable water.  i wish i had a picture of it.

Now on the other hand, my boat is still doing some funkyness... i am 100% sure we fixed the electrical problems. and im 100% sure we put the pump back together right.

However, when i hit the gas, the boat jumps out of the water and takes off... gets up to speed and holds full throttle for a good 1/4-1/2 mile, then it feels like the fuel has been cut off, and it boggs down... i can give it 1/2 throttle and it will cuise on plain all day long.. but as soon as u run it hard for a min it starts feeling like its not getting the fuel it needs. ive touched 50mph even with it not running right  :smile16:

The trouble shooting that i have done includes, checking the fuel filter (it has lots of flow and is not clogged, sprayed b12 in it too.), changed the pump with a newer "High volume" fuel pump that came off of a car motor. and i have taken the carburetor air horn off, and adjusted the floats to the edelbrock book specs. Ive also tried the 3 different pump accelerator settings, all of wich have yielded no difference in issue.

other than that everything else is working great.

 

[Disturbed]

I would suggest trying a Holley.  The Edlebrock fuel bowls are too small for that long of a hard run.  $.02

 

[Last Mohecian]

Do you have a fuel pressure gauge?  Is the pressure falling off?  Sounds like you are making good progress now.

 

[NescherMonty17]

I would suggest trying a Holley.  The Edlebrock fuel bowls are too small for that long of a hard run.  $.02

hmm... i was hoping to not have to buy another 400+ dollar carb, but i guess if its just physicaly too small im gonna have to.  I was hoping that someone would have an ahh-ha moment, and tell me to bend somthing or turn a screw to fix it. 

i did get a chance to pull a skier once, and i was amazed at how it was uneffected by the skier, yanked his fat ass right out of the water and held 30 like it was nothing..

 

[NescherMonty17]

Do you have a fuel pressure gauge?  Is the pressure falling off?  Sounds like you are making good progress now.

no and i didnt think about this until i was already at the lake... but i am defenetly going to look into it, i thought the new fuel pump would have fixed any pressure issues... but it didnt change anything.

 

[ChryslerJet]

Matt and Tim have you on the right track on make sure you are getting good fuel pressure and volume all the way up through the rpm range.  The bowls are smaller but if the fuel pump can keep up it shouldn't matter.  If the pump and pressure are fine then go get a new carb but I would start back at the fuel pump or go to the pickup in the tank.  Also could check if you have a check valve at the tank and remove it

 

[NescherMonty17]

Matt and Tim have you on the right track on make sure you are getting good fuel pressure and volume all the way up through the rpm range.  The bowls are smaller but if the fuel pump can keep up it shouldn't matter.  If the pump and pressure are fine then go get a new carb but I would start back at the fuel pump or go to the pickup in the tank.  Also could check if you have a check valve at the tank and remove it

FUEL TANK PICKUP??? lets talk fuel tank then... bc i had problems in the benining with the fuel level sending unit, and i took it out and cleaned it.. it was kinda rusty and gummy... but a little b12 and it was working again.

so... fuel tank pickup? what should i look for?   

also, while we are on the subject of fueltanks.. my boat has a vent on the side that seems to dump large quantities of gas out. is there a better "venting" solution? id hate to pulute the water un-nessesarily by making a hard left.

 

[ChryslerJet]

Matt and Tim have you on the right track on make sure you are getting good fuel pressure and volume all the way up through the rpm range.  The bowls are smaller but if the fuel pump can keep up it shouldn't matter.  If the pump and pressure are fine then go get a new carb but I would start back at the fuel pump or go to the pickup in the tank.  Also could check if you have a check valve at the tank and remove it

FUEL TANK PICKUP??? lets talk fuel tank then... bc i had problems in the benining with the fuel level sending unit, and i took it out and cleaned it.. it was kinda rusty and gummy... but a little b12 and it was working again.

so... fuel tank pickup? what should i look for?   

also, while we are on the subject of fueltanks.. my boat has a vent on the side that seems to dump large quantities of gas out. is there a better "venting" solution? id hate to pulute the water un-nessesarily by making a hard left.

Well first the vent should not be dumping gas out.  Check that out not sure what's going on there.  Maybe it's hooked up wrong take a look at the tank and take some pics of all the lines.

Next take off the fuel line from the tank.  Take a piece a flexible wire and run iit down into the tank if you hit a ball take that fittiing off and replace it with a regular 90 fittiing.  To check thee pickup run a wire down through to the bottom of the tank to check for blockages.

 

[jerjrvette]

Sounds like the tank is not vented. You might be pulling fuel out for a while but when the tank pressure is equal to the fuel pump vacuum you are going into an airlock ! If vent is not blocked add another one. Hope my guess helps, Jerry

 

[ChryslerJet]

Sounds like the tank is not vented. You might be pulling fuel out for a while but when the tank pressure is equal to the fuel pump vacuum you are going into an airlock ! If vent is not blocked add another one. Hope my guess helps, Jerry

I am almost wondering if the vent is tied into the supply line or smething because the only way it would be dumping fuel is if the vent is hooked up to a connection that is sitting in fuel.  The vent connection on the tank should be only grabbing air at the top of the tank and would see fuel only when the tank is full.  I would look at the vent hose and I would set it up so there is a loop in it and make sure it's not connecter to another hose unless it the filler hose. 

 

[Last Mohecian]

You can check to see if the tank is vacuum locking by simply opening the gas cap.  If it runs great with the cap open you have a venting problem.  If fuel is spilling out the vent I doubt it is clogged.  The fuel spillage solution may be as easy as not filling the tank so full.  Before doing any of that get a gauge on it.  You need to know if the pressure is dropping off to know where to look to fix it.

 

[Last Mohecian]

Here are a few things to check assuming fuel pressure is falling off.

Tank Vent - check it by opening that fuel cap and run with it open.  If the problem goes away the tank vent is clogged.

Fuel filter - This is a simple one to replace.  Even if it is new you may have picked some crap up and clogged it already.

Fuel pickup anti back flow valve - The ones of these I have seen are in the fuel barb connected to the 90* that goes in the top of the tank.  You can pull the barb off and look through it.  If you can't see straight through it has the valve.  You could also do like CJ suggests and try sticking a piece of wire through it.  You will have to check the length of the wire and see if it goes all the way through the barb.

Fuel pickup sock - Many of the fuel pickups have a "sock" or screen on the end inside the tank.  You can try using compressed air to blow back through the fuel line and pickup.  Sometimes this will dislodge what ever is clogging it.  This is not a permanent fix.  If there is crap floating around in the tank it may eventually clog again.  The real solution here is to have the tank cleaned.

Air leak is fuel line - This one is a little more difficult to diagnose.  You need to put a piece of clear line as close to the carb as possible and monitor for air bubbles in the line.  If you get this far we can go into more detail on how to check for this.

You may have already said but are your tanks metal or fiberglass?  If they are fiberglass you have a whole new set of issues.  The ethanol in our gas dissolves the resin.  The only solution here is to replace the tanks with metal ones.  The coating that claim to work don't and just create a bigger mess.

If the fuel pressure is not dropping off you could try a set of high flow needle and seats. I personally have never seen a need for these on a build as mild as yours.

http://www.summitracing.com/parts/EDL-1466/

 

[NescherMonty17]

im gonna pull it in the garage and go over a few things... ill take some pictures of the gas tank and its hook ups.... its a metal tank, but looks aged.  I really think it could be an issue with the tank... i can picture in my mind these issues being present on my boat.  I dont see why this "set up" shouldnt work. granted its still car parts. ive had this carb on a z28 camaro that ran mid 12's and could touch 160mph. so it being a stock 350, i dont picture it being too small.  but the tank issues yall speak of are setting off lightbulbs so im gonna unpack this morning, and then get after it.

the carb on my boat is BRAND NEW, as well. so its not like it could be dirty or need a rebuild.

 

[72hondo]

What fuel pump are you using? Unless I missed it what's the fuel pressure set at? Is there a regulator?

Eddys out of the box are notorious for the floats being off. There set too low. I think it's supposed to be a 5/8 drop.

The acc pump holes have nothing to do cruising or once full wide open. There mainly used for extra fuel outta the hole.

When you say high volume, that usually means a regulator is required.

 

[NescherMonty17]

What fuel pump are you using? Unless I missed it what's the fuel pressure set at? Is there a regulator?

Eddys out of the box are notorious for the floats being off. There set too low. I think it's supposed to be a 5/8 drop.

The acc pump holes have nothing to do cruising or once full wide open. There mainly used for extra fuel outta the hole.

When you say high volume, that usually means a regulator is required.

ok, then i might be using the wrong terminology.  The pump i am using came off of a running 383 stroker with an edelbrock carb.  It came out of a car, and i just hooked it up like the original was in the boat.  it looks the same as the one that came off, its just a little bit bigger and newer looking.    i was told it was "high volume"

im not sure what fuel psi im getting yet, i have yet to purchase a guage. and there is no  regulator that i am aware... im going right now, getting off the couch, and pulling the boat in for inspection... ill post pics in a few!

 

[NescherMonty17]

Ok here it is... the pictures of my fuel.

 

[Last Mohecian]

That vent looks like it may be clogged.  Open the gas cap and see if you can blow air through the vent.  You should be able to hear it if you listen close to the cap.  That fuel hose barb on the tank may or may not be anti siphon.  They look the same externally.  Only way to know for sure is to take the fuel line off and check the barb.

 

[KONA77]

i would say if you have fuel coming out of your Vent,  not clogged,  now if that is happening the you have and old style vent,  there are new types that prevent this from happening,  but the solution to it is not to fill the tank completely fuel like you would a car,  i've experience what your talking about,  i fill my boat by the fuel gauge and the capacity of the tank..... 

i think you primary concern should be with the pic up tube,  and yes most older tanks will have a screen on the end of that tube,  but your gonna need to pull the tank, 

i used an electric fuel pump to empty my tank,  by disconnection the fuel line at the filter, and connecting the electric fuel pump and pump the fuel into the container, if there is a restriction,  it will it could show up while pumping full out with this method.....

hope this helps

 

[customtouch]

EPIC MEMORIAL DAY WEEKEND @ UTE.    Saw the sickest jet boat throwing a mind blowing roostertail that just engulfed the entire cove with "lake mist". It was turbo charged, and topped 101 mph on less than admirable water.  i wish i had a picture of it.

Is this the Ute Lake in New Mexico?

 

[HellinnFrnt]

hook that return line up to the tank too you may be building pressure and flooding the bowls at speed ... it can't be good for the diaphram either.