Carbed 351 stalling on skier take-off

You know, I was going to say something when I first saw this but I figured I'd let it play out a bit. Seems to be a rash of this lately.

Tom;
Take a look at this and set up your idle mixture, accelerator pump shot and timing as described and you should be fine. I would also move the accelerator pump cam back to the original position too. You've proven that adusting the accelerator pump is helping your problem, so let's get things adjusted the right way and see where we're at.

TomD wrote: . Also, what is a WOT figure?

Tom, Sorry. WOT is the "wide open throttle" RPM. It's the figure needed to confirm the prop is correct (if the engine is performing).

Change your fuel filter and water separator if you have one,steady stream from the accelerator pump is good but check your float also.I had the same issues last year,and the culprit was those mentioned.

TomD wrote: But here is my problem... when I push the throttle down hard for skier start-ups, the engine jolts and then stalls almost every time. If I baby the throttle by pushing down very slowly, which is hard on the skier to be dragged for those few extra seconds, then I can avoid the stall and the engine will accelerate to cruising RPM and run like normal. Additional things to mention that could be factors... (1) the boat has a new prop which is a 13x13 RH.

I am wondering if it's not too much prop.
Also, you really should not need to push the throttle down hard for a skier to get up. The skier will thank you and so will your engine.

I'm not saying you don't have a stalling issue but what I am getting at is that this may contribute to it.

My boat had the same issue under load and turned out to be bad gas. Once we drained the tank and ran fresh gas through the system we were good to go.

The boat I'm working on is a 1977 Ski Nautique with a Ford 351w

First off, over the last few years I have made a big mistake by not running ethanol free gas. I have now switched to only using ethanol free and I am treating all my fill-ups with seafoam.

A little more background... this Spring I installed a new fuel pump because the engine would not start and I was able to diagnosis that it had absolutely no fuel pressure. The new pump made the engine start like normal and overall it seems to be running very well. I'm experiencing easy starts, smooth idling, no black residue at the exhaust tips, normal operating temperatures and normal power at cruising RPM.

But here is my problem... when I push the throttle down hard for skier start-ups, the engine jolts and then stalls almost every time. If I baby the throttle by pushing down very slowly, which is hard on the skier to be dragged for those few extra seconds, then I can avoid the stall and the engine will accelerate to cruising RPM and run like normal.

Additional things to mention that could be factors... (1) the boat has a new prop which is a 13x13 RH. I put the prop on two winters ago and I had this same acceleration/stalling issue last summer before I installed the new fuel pump (2) My gut tells me that I now have a bad accelerator pump (possibly from the ethanol), however, I recently looked down the barrel of the carb while my Dad pump the throttle and I can visibly see gas squirting, so the accelerator pump is at least pumping some gas, maybe not enough? (4) the coil, wires and plugs are all new within the last 5 years and have low hours on them (3) lastly, since installing the new fuel pump I have not made any adjustments to the carb, engine or anything else

Does anyone have any thoughts on this issue that might help me avoid calling my boat mechanic? I'm motivated to try fixing this one myself if possible...