Throtlle up, engine down...

[Good Grief]

I have a 97 1/2 290 sundancer. Twin 4.3l, carbeurated I/O. I leave the slip and its 15 minutes unti lI'm out of the 6pmh/no wake zone. When I push the throttles forward to get on plain, the engine dies. My 'interim solution' :huh: is to slip the engine into neutral and pump it once to get 'past' the stall point, then once back at idle, back into gear, and off we go, no problem.

New fuel filters (clean and water free after removal) Plugs/caps/wires a year old, always run fuel additives in gas. Any experience with a problem like this? One fellow boater recommended replacing the fuel filters that are on the carb inlet where the fuel line attaches. I'll probably do that because I haven't done it yet and it is inexpensive. Any other suggestions? :smt100

 

[Steve04]

Good Grief,
it sounds like a fuel problem, and if you haven't replaced the inline fuel filters I would do that first. question can you idle all day long, and only when you give it gas does the engine stall? if so the engine is not getting enough fuel. though I am not a mechanic that would be my first suggestion as well. I had the 4.3L and they are great engines, though I did not have a 98, I had a 2001 fuel injection, if you have carbs, then the next step is the high speed jets in the carbs are clogged.
the new gas with ethonol is just s---t for our engines. that's you next step.
Good Luck Steve

 

[rowekmr]

Once you get past that hesitation if you bring the throttle back down later will it do the same again when advancing the throttle? Are they carb'd or FI?

 

[Good Grief]

Yes, I can idle all day long. I can ease the throttles up, no problem. It's when I go from idle to full throttle that it stalls, no cough, no sputter, just fizzles out.

 

[Good Grief]

If i'm on plane and come off plane to cross a wake or whatever, I can go right back to plane. If I idle around for a while, same problem. I haev carbeurators.

 

[tdappleman]

Which carbs do you have? I had Weber 9600's on mine - one was replaced with an Edelbrock 1409 which is almost the same carb - down to the 'W' stamped into the housing. A couple of questions before you start taking things apart: When you advance the throttle to WOT does the accelerator pump squirt fuel? Has the carb ever been apart and cleaned? Do all of the linkages move freely? Is the choke opening and closing correctly?

The Weber/Edelbrocks are a bit sensitive to float adjustment - so if they have never been apart and cleaned and adjusted I'd start there. They are pretty easy to get apart and cleaned up - you'll need a torx driver to get the 2 halfs of the carb body apart. Here's a link to assist you.

 

[Good Grief]

one would think i know... I'm going to have to do a little research and come back. Probabbly will not have anything to post until Friday 7/24.

When you advance the throttle to WOT does the accelerator pump squirt fuel?
do not know. i'm guessing i check w/ engine not running?

Has the carb ever been apart and cleaned?
not in the 2.5 years i have owned it.

Do all of the linkages move freely?
2nd thing to look at.

Is the choke opening and closing correctly?
3rd thing to look at.