Engine surging / won’t go above 3k rpm

[Stevo1989]

Quick back story about two years ago(2016) I bought a 1990 Ski Nautique 351w that had sat for roughly two years. Prior to me buying it there was a EI put in. After buying it we found out it was only running on 4-6 cylinders . Changed the plugs had a compression test done( came back fine) and had the timing redone. After that it began to pop through the carb so I sent it out and had it rebuilt. After getting it back it would still pop and sputter. So I swapped the 600cfm holly for a 600cfm quickfuel carb. When swapping the carbs I had to change from the original fuel line to a slightly longer flex line. This eliminated the popping and the boat ran great for about 2-2.5 hours when it just randomly shut down while cruising around 3000rpm ( like someone turned the key off) and wouldn’t restart. Took it to the marina where they discovered the gear on the bottem of the distributor sheared off.so I bought a new distributor new cap, coil, plug wires , rotor, and fuel water separator and had it re-timed again. Took the boat out yesterday for the first time and it fired up and ran great except when cruising it seems to not want to go above 3k rpm and there’s a slight surge like it’s trying to give me more but can’t eventho it should after cruising around at different rpms when I went back to idle (set at about 900rpm) it dropped to 500rpm and was surging and sputtering. Readjusted the Idle back up and that seemed to smooth out but there is still a surge at high and sometimes low end . Would this be fuel/air adjustment or possibly linkage adjustment ,a air leak bad fuel pump or something that I’m not even thinking about. I’m going to pull the plugs tonight and check them to see if any are damaged or fouled ( new gas with ethanol treatment prior to taking it out) thank you in advanced

[Nautiquehunter]

Sounds like multiple problems . You may have covered up the original problem by replacing all those parts? First what distributor and EI do you have?

[Stevo1989]

I’m drawing a blank right now but it started with a p

[Stevo1989]

Yea the engine surging was never there before when the boat was running right the few times it got out until changing the fuel line and carb I haven’t checked the fuel pressure not sure if the slightly bigger line is to much for the original pump or what’s going on. Originally I only replaced the carb when the distributor sheared off I had already had the electronic tune up stuff just Incase (bought prior to the new carb) and I left them at the marina Incase he needed any of those parts at that point didn’t know the gear sheared off just that it was electrical issue. But I guess he decided to just swap all of the old out with the new I would have rather done piece by piece as a process of elimination

[Stevo1989]

Prestolite screw down capdistibutor and protec EI I believe . The carb is still factory set I didn’t want to mess with anything unless I knew that the problem could be cause by the fuel/ air screws not being tuned right being as it’s only low end and very high end but smooth as butter on a hot plate on launch, pulling a skier and up to about 3/4-7/8 throttle then beyond that I gain nothing speed power or rpm wise but will get short surges less than a second where it feels like it’s trying to give more

[Jeff b]

Look to see if check valve in fuel tank is working properly. Mines a 79 and was froze up. Not sure if your year has one.