Popping from carb and loss of power when going over 10mph

[Stevo1989]

I purchased a 1990 ski nautique with the 351 pcm and Holley 4barrel carb.i changed out the fuel water separater and the plugs and the boat ran great for the first few trips out.
after that it started to pop really consistently from the carb. The next time I took it out everything ran fine and we skid and tubes most of the day on the way back to the dock it started to pop again. Then when I took it out the other day we could barely go above 10mph without the carb popping again .. any suggestions it ideal fine and revs fine in neutral

[Nautiquehunter]

Check ignition wires cap rotor coil.

[Skidave]

Is this model year engine still have a normal distributor ignition (pre Protec ignition)? If so, check your timing after looking @ wires, plugs, etc. Your timing may be a bit off. You will need a timing light and your manual or info from a manual for your timing. If you have a lot of hours on your engine, you may have to dial your timing a bit. I had a '79 with quite a few hours. The base timing was a few degrees off what the book called for. I used that few degrees to help set everything and I was good to go.

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[Stevo1989]

It has an electronic ignition I'm not to sure on which one and he boat has roughly 550 hours on the meter. What confused me is that it had the popping problem and then we changed the fuel water separater filter back out and I ran beautifully for probably 2-3 times out then started to pop again I was thinking maybe the inline filter is clogged it seems like it's not getting the fuel it needs I still need to pull the plugs out and check and see if they are carboned or still clean tho I haven't had to much time to mess with it . I was guessing since it was popping that the power valve probably is shot at this point so I ordered a carb rebuild kit just in case

[Mikeski]

General mechanical knowledge points to a lean condition whenever there is popping through the carb. You could also get this from crossed plug wires but that condition would appear after some maintenance when things were not properly re-assembled. Pull the carb off and head to Napa. A standard 4160 rebuild kit should work with the exception of a different sized powervalve if my memory serves me correctly. Have them match the existing powervalve and you should be good to go. Take note during the rebuild, you want all jets and valves to be sized the same as what you take out. This is where there are some differences in the marine tuned carb. Rebuild kits typically sell for about $25 if you don't get the one in a fancy box. Commonly sourced from Ebay too.

Anybody with basic mechanical knowledge can rebuild these carbs. This was the first carb I ever took apart as a teenager when I rebuilt the carb on our 1983 Ski Nautique. Not much has changed on these carbs.

[Stevo1989]

Along with the popping this is the second time that my third cylinder on the steering wheel side has blown the center out of the spark plug ?? What causes this ?

[Stevo1989]

Have had the carb rebuilt (kit had a bad power valve) so I had it rebuilt again just ordered cap rotor coil plug wires and plugs hopefully this will fix the problem if not I suppose next would be carb/ fuel pump. Boat had a prestolite electronic ignition put it and was never re timed so I had that done along with a compression test new fuel water separator and new plugs which kept fouling out on two of my cylinders. Will I have to retime it after changing the rotor cap and wires ? I also seen that sometimes the nylon gear goes and the boat could jump timing recommendations? I’m about at ends wit with tying to get this thing running right