New to Wellcraft 3400 Express Cruiser

[Billm]

Sounds like the port engine is holding back the other one from reaching 4000 rpm. So what is wrong?

Some quick and easy checks:
1. Secondary throttle plates stuck
2. Distributor weights rusty and not advancing
3. Oil lever too high

Other possibilities:
1. Restriction in the fuel system
2. Bent propeller blade
3. Time for another valve job. Already?

That’s about the limit of what I can help with. Interesting that all those years at 20 mph and you already picked up 3 mph just by cleaning the bottom. Definitely something wrong with an engine that won’t go over 3100 rpm. Have the props ever been scanned? The goal is to be able to cruise easily on plane at no more than 3000 rpm with the synchronizer needle pointing straight up.

You may want to bring that idle up to about 650 rpm. Helps with the docking.

[ExplorGM]

Thanks for the suggestions Bilm!
I do recall the 2nd owner mentioning that he replaced at least one of the carbs with a Holley Marine unit because of a stuck secondary... Can't remember if he said both or only one... Will have to check them out.

My biggest issue I have with this boat is the weight and challenge of removing the floor boards to ge to the motors. The carpet is tacked at one end and they have to be pried upward, fingers inserted, then wiggled out foward then angled around an obstacle and finally lifted clear and leaned somewhere were they won't slide down and fall over. Takes longer to remove than to do the work below! I looked at an older Formula 29 that had powered struts for their hatches... Envious!

I am adding a back up bilge pump (110v) to the aft one (12v) as it seems tempermental. I'll check the carbs at the same time. Setting up the 110 unit to light off first while connected to shore power so that it will save some battery power/life.

I did check the oil when we first took possesion and it was full but I'll check again in case I missed an overfill indication.

I doubt anything has been done to the props. Nothing in receipts and neither owner mentioned it. I'll check with the guy that cleaned the hull as he also checked my anodes (kinda personal...). He may have noted a prop issue. We moved the boat to cleaner water so I can also get down there and check.

Hopefully no more valve jobs for a while! It has hydraulic rollers so they should pump up to adjust if not obstructed or collapsed?

Thanks again for your help!