Carver Owners Forum

Motors are 350 crusaders with recently rebuilt carbs, manual says max rpm should be between 4000 and 4400 rpm. Refinished the hull with new antifoul in January so hull should be clean. I believe the props are 18 x 19 four blade. During sea trial motors wouldn't get over 3000 rpm. Seemed like they were bogged down working too hard. Boat wouldn't do more than 11 knots. Maybe the props are not sized right? Anyone know how to find what the original size and pitch should be on this boat?

Welcome to the forum....

How long did the boat sit in the water after the bottom job, you are in salt I'm guessing here. Recently rebuilt carbs, was wide open throttle checked, are they opening all the way....somethings to check.....good luck with your purchase.

Thanks, boat has been sitting in fresh water since bottom was done and motors rev up to 4000 in neutral.

First thing to verify is that the bottom is clean. You can grow a lot of stuff in a few months, even in fresh water. Then verify prop size and pitch, I don't know what that boat would have had? Then fuel filters and a complete tune up.
That boat should top out at over 30mph with a clean bottom and good running engines.

BTW, revving in neutral doesn't tell you anything, and is not good for engines if done for more than a second or two.

Good luck!

Trim tabs working?

Have you already bought the boat or in the process? Ok, you sea trialed, what about a survey? What does the owner say about not getting up to speed? If it is over propped, why did the owner do it and how long ago? Agree, that boat should easily hit 30 mph and if it won’t, don’t buy it until you get answers and the issue is corrected.

Those are the correct props for that engine. My first thought would be bad fuel, check for water in the fuel filters. I would go back to the rebuilt carbs and make sure they are set correct. Full tune up is a great idea. Check throttle cables to make sure they are not stretched. That bottom could still be fouled up, especially if the boat was just sitting in slip since January.
How many hours are on the engines? Are they both performing exactly the same? er

Does that still have distributors? Does it have mechanical advance? If so, check and make sure they are working, either by taking the caps off and seeing if you can twist the rotor one way and it snaps back to the original position, or by checking the timing when you're raising the RPM in neutral.

I would think that boat should be able to get on plane at 3000 RPM’s, certainly more than 11 knots.

buster53 wrote:Source of the post I would think that boat should be able to get on plane at 3000 RPM’s, certainly more than 11 knots.

Generally true, the tipping point seems to be around that rpm so long as the engines are making enough HP to push the boat on top. We will have to wait and see the result of rbutler's investigations regarding the carbs/boat bottom/tuning condition etc. Oddly enough here the boat should have been pulled for the survey, then the bottom and props would have been documented. His explanation of the engines bogging and just pushing water is telling, we will see. I know on some carbs the power piston will do this, and the secondary lockout tab will stop the secondaries opening until the engine is warm, that tab needs to be adjusted so it works correctly all the time with the choke heater.