Towing problem

« **on:** August 31, 2008, 12:05:20 PM »

I have been having problems with my engine losing power around 3500 RPM's when I am pulling the tube. I ran yesterday for several WOT passes and it ran perfecty. 67.7 on GPS @ 5600RPM's on an A cut When I add drag to the boat though it runs perfectly up to the 32-3500 mark then I can hear and feel the motor "bog" down. I can floor it and get it going again but it will return to the "bog" when it gets back to the mid RPM's. I thought it was a fuel delivery problem initally and replaced all the fuel lines and cleaned the electric carter fuel pump. It had rust debris in the screen. It seems to work fine even in the problem RPM's for a few minutes, but once it starts even shutting down and letting the fuel pump run for a bit does not stop the problem. Anyone have any ideas as I am stumped and am leaning towards a pump issue now?? Could the loader be over loading?

Thanks for any and all ideas on this.

« **Reply #1 on:** August 31, 2008, 12:57:30 PM »

Fuel delivery , you have dual carbs dont you .

-beerjet-

« **Reply #2 on:** August 31, 2008, 01:39:51 PM »

yes dual now, looking for a new pump, holley red, as we speak will that be enough or do i have to get a blue?

« **Reply #3 on:** August 31, 2008, 02:33:26 PM »

I think your problem starts with F and ends with d

« **Reply #4 on:** August 31, 2008, 04:06:32 PM »

Quote from: Marlin on August 31, 2008, 02:33:26 PM

I think your problem starts with F and ends with d

x2

« **Reply #5 on:** August 31, 2008, 08:51:36 PM »

On the contrary, I am certain the only reason it's still trying to go and not giving up on me is bacause it's a FORD

I installed a new fuel pump and noticed that the fuel pressure gauge sits at a steady 7lbs now (not running) it bounced the needle rapidly between 4-8 with the old one, I thought that was normal

Will see if the problem is cured tomorrow.

« **Reply #6 on:** September 01, 2008, 02:03:43 AM »

Mid range performance can be a lot tougher than WOT. A tube really loads the motor and requires more power than un loaded flat out. Which dual carbs are you running? I know I have found every Edlebrock AFB/AVS type carb has the floats set too low out of the box, and a heavy load requires more fuel than a WOT charge un loaded. The toughest test of performance is a mid range, medium RPM, heavy load. Kinda like expecting you freeway flier to perform with the "E" brake on........MP

« **Reply #7 on:** September 02, 2008, 08:01:16 AM »

New fuel pump did not correct the problem, I have 2 holley 600's. The floats were set to have the fuel level right at the bottom of the "viewing" screw hole. I will remove the carbs and look for debris. I didint realize that a jet pump could tell the difference between extra drag or not. I thought it just pumps the water according to how fast the motor is turning, and overall speed/acceleration were the only thing affected by drag. The engine still turns the pump between 32-4000 RPM's but the power loss in this area is very evident. It just sounds and feels like it is bogging down.

« **Reply #8 on:** September 03, 2008, 05:48:50 PM »

Carbs have been cleaned out, nothing visible as far as debris. I tore up some gaskets and an o-ring so those got replaced, and the floats were set to almost not open

I am hoping that was my problem. I set them about 1/2" from the top of the bowl and will try that. What will happen if they are too high? They dont blow fuel out of the vents at their current settings but could be above the view screw hole.

« **Reply #9 on:** September 04, 2008, 10:37:04 AM »

OK, first off, with the bowl inverted, meaning upside down, set the top of the float, (actually on the bottom now), parallel to the bowl. That is very close. Now turn it over and check "float drop". Make sure the needle can drop out of the seat, and there is a number for this measurement. This is adjusted by the "tang" which actually stops the float drop before the needle can get off center and hang up. Sounds like you're finding things out for yourself. Dual carbs are bitchen, but do require a little more work to get them dialed in............MP

The Chaz

Towing problem

beerjet

Re: Towing problem

The Chaz

Re: Towing problem

Marlin

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shawnthedrifter

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The Chaz

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Moneypit

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The Chaz

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The Chaz

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Moneypit

Re: Floats