Poor water circulation??
 

Our boat started to sound funny at idle last Friday after several hard runs. At first I thought it may be vapor lock and went home. The next day I brought the family out for a day of boating and the boat sounded funny again when I started it. I looked at the transom to see if water was properly exiting the exhaust and noticed the starboard side exhaust was pulsating water as usual but the port side exhaust had a little stream of water trickling out almost like the Corsa Captain's Call was engaged just on the port side. I thought the impeller may be damaged and had our local mechanic replace it. He replaced the impeller and checked hoses and such for proper water circulation. He said the impeller he replaced looked fine and he could not find any problems at all with water circulation. He said he fired the motor after he replaced the impeller let it run for a while and everything looked good. So my question is why would water be trickling out of the port side exhaust at idle? The motor is a 2000 454MAGMPI w/ aftermarket cam, exhaust and valvetrain w/ Corsa Captain's Call. Thanks in advance for any insight.

Rob,

I cant think of any reason why an impeller would cause uneven water flow from the exhaust pipes. I can see it slowing the flow to both pipes, but not just one. There must be another culprit here. Did the engine just sound funny or did it run bad as well? Any chance of reversion on the one side? Maybe an exhaust system problem?

Vinny

Just sounded funny, ran normal at cruising speeds. Water reversion is a big scare. I do not want to cause damage to the motor as a result of reversion. I am almost ready to loose the Captain's Call just as an insurance policy.

I would be concerned about the possibility of reversion as well. Is there any signs of water in the oil? If it happens again, pull all the plugs and check for water on the plugs or in the cylinders.

Is the engine idling too low? That would cause reversion very easily. Did you talk to Tyler Crocket?

Engine is idling at 700rpm. I have not talked to Tyler since this has happened.

check for the little balls on the spring shaft in the water outlet housing. sometimes they rot out or get stuck, and diminish flow

Try Back Flushing All The Lines. Could Be Some Sort Of Blockage On That Side.

What type of aftermarket exhaust? We used a Stainless Marine manifold system one time and after losing an engine due to detonation/overheating at a specific cylinder, Stainless Marine told us that sometimes their fittings are too long and bottom out against the internal surface of the manifold. Sure enough, that was the culprit. The engine we lost detonated in the cylinder closest to the blockage, a valve broke and went through the rest of the engine. With the new engine, we cut down the fitting, and no more water flow problem.

monstaaa has the fix, check those balls and spring assembly. Look for rust or scale in the exhaust system after backflushing.

Check if the Captains Call has hung up on the port side, if not try to back flush the hoses on that side.