94 Ski Nautique Engine hesitation

Lots of great info guys. Thanks. I have a growing list of stuff to check.

Answer a few of the questions:
1. The engine only hesitates for a few seconds or less. Once it pulls through it has never had an issue revving right to top speed (~47 ish).
2. It has never gone into limp mode.
3. Yes, it was a Holley Marine rebuild kit. but it only came with one power valve. I don't recall if it was the same as what I pulled out but I do know that there was a ton of online chat about which one to use. If it was changed by one size, would that trigger an issue? The hesitate was there before the rebuilt and was actually the reason I rebuilt it. I didn't notice any performance change after the rebuild.

I never had to deal with the FCR. I ran two strokes (38PWK) until the 4 strokes were EFI. EFI just makes life easy vs jetting for weather and altitude.

Gary S wrote: There is a saying, 90% of carburetor problems are electrical.

And about an equal number of ignition problems are carburetor/fuel

Did this issue come on like a switch or was it a gradual progression?
When not towing a skier if you ease into the throttle just right will the motor eventually allow full throttle at some point?
From what I've read it sure sounds like fueling, when you rebuilt the carb did you use a "Holley" marine rebuild kit? If so that kit would've likely came with two power valves so I will assume you replaced your old one with one of the new ones.
If you know four stroke motocross bikes than you well know the awesome Keihin FCR-MX carburetor. That carbs accelerator pump tuning is absolutely critical, so try to treat your boats Holley in the same fashion.
Just my 2 pennies!

Good luck man!

I'll read more about the Protec as the thought has certainly crossed my mind. Right or wrong, the reasons I haven't concluded its it protec:
1. The issue exists when stone cold, right off the trailer. But the issue does get worse as everything heats up.
2. The dealer "tested" the protec ignition after an hours worth of run time on the boat (fully up to temp) and didn't detect any issues with the protec (and to be fair found no issue at all. ...)    

It took 14 minutes for somebody to blame it on the Pro Tec system.

Slow day on CCF

For CRPilot google 'Correctcraftfan Pro Tec and do some reading.. You've got a few weeks to get thru it all   

Whether it's the problem or not, it'll scare you

Thanks for the vote of confidence on my abilities! I've raced motorcyles and rebuilt my own 2-stroke and 4-stroke motorcycle engines for 20+ years so I have the basic skills to attack some of these issues. What I lack in the specific knowledge of how the 351 fuel and ignition systems work. Not the same as a single cylinder thumper...

Forgot to mention this is the Proboss HO so it has the protec ignition. No points to check and to my knowledge no wear parts to replace. Not sure if there are other validation checks for it.

Yes, I reset the accelerator pump squirt per the spec'd gap. Don't recall what the spec was but it was checked and there is a solid squirt of fuel when moving the throttle open.

My boat is currently in storage but I'm taking notes of what to check when I can get to the boat:
-Recheck accelerator pump adjustment
-Anti-Siphon valve (hoping there is a "how-to" on line somewhere)
-Fuel pressure - What pressure should it be and are there any in-line gauge kits that would be recommended?

It'll be 3-4 weeks before I can get to the boat to start looking at this but if anyone is looking for a fun spring project I have one....

I'm not from around there, lots of people in your area. But, when you say you don't have the expertise, I'd be very surprised if someone who successfully rebuilt a carb can't do all of the above troubleshooting themselves. Nothing of course wrong with getting some help though!

I'm looking for some help from the local experts. I've been chasing an engine hesitation for more than a season now and I've given up with the local dealers who "can't duplicate" the issue.

94 Ski Nautique PCM 351 Carburated with about 450 hours. The engine starts and idles good but can be a little cold blooded typical to carb'd engines. Once warm, but not completely head soaked, the engine will have a very distinct cut out when pulling a slalom skier up. More throttle = more cutout.   After a second to two it catches and pulls up to and maintains cruising speed. Hard acceleration from 25-36 will trigger the cutout as well. A slow, low load acceleration will not cut out.

It feels like someone pulls the tether for a second (checked that though ans its tight).

After skiing for a bit the cutout gets worse as the engine completely heat soaks. At its worse I can't even pull skiiers up. At that point it feels like its missing on a cylinder or two.

The carb's been rebuilt (by me) which had no impact on the issue what-so-ever. I wouldn't rule out carburation thought as it feels like a fueling issue to me.

I've read a ton and there seems to be a list of potential issues but I honestly don't have the right tools or in some cased the mechanical expertise to diagnose the problem if I'm staring right at it.
-Fuel pump - original
-Fuel filter (replaced last year)
-Fuel tank check valve?? (not sure what that is)
-Accelerator pumps?
-Probably many other possibilities...

That's where I need someone that is good at trouble shooting. I'm located just west of Milw Wi. Does anyone have a recommendation for a person/mechanic that I can take this too? Or anyone close by and willing to meet me on a local lake and trouble shoot (when the ice goes out)?

I don't want to loose another summer to frustration.

Looking forward to getting this solved.

Jim