Will Flappers in Silent Choice Lower Y-Pipe let water in the motor if broke?
 

Had a problem this weekend. Boat ran fine all day then stopped for dinner. Started it up and planned off and overheat buzzer went off on port motor (502efi). Figure i wrapped a bag around the drive. I Shut it off and put the other motor in reverse to try to unwrap the bag. When i went to re-start the motor it was hydro-locked. i pulled the plugs on the outside Cylinders and the were full of water. other side of motor, cylinders were dry.

I figure i may have blew a head gasket, or possible exuast manifold leak (i have stainless marine manifolds). I pulled the manifold and pressure tested and found a pin hole that was leaking water inside. I dont think that was this problem because of the extreme amount of water in the cylinders and manifold itself. I then pulled the head on that side and everything looked fine with the gasket. And there were no signs of water anywhere in the motor besides the cylinders. Oil is still a normal color everywhere i looked, and pistons were not "washed".

I looked down the "Y" pipe and noticed the one way rubber flapper was broken off on that side. I am beginning to think there is nothing wrong with the motor or heads, and the water came into the motor through the broken exhaust flapper in the "Y" pipe and dumped into the cylinders when i put the boat in reverse to try to free the bag (cause that motor was not running).

Is this possible if the "Y" pipe flappers are broken? I will be replacing the manifolds why they are off. Will stainless marine cover these manifolds under thier 5 year warranty because of the holes that i found?

Re: Will Flappers in Silent Choice Lower Y-Pipe let water in the motor if broke?
 

Sorry to hear this Mark,

Is this the one they had apart???

I would think it would take quite a bit to get water up the pipes like that, but then again, those flappers are there for a reason......???????????

Re: Will Flappers in Silent Choice Lower Y-Pipe let water in the motor if broke?
 

Just my .02

But I've often wondered why they are there.
I understand normal straight pipes out the back and the
possible wave which could surge your system.

But with Y-pipes yes water will seek it's normal level.
But I can't really see any underwater current's strong
enough to surge through your prop hub and or gimbal
houseing. And still be strong enough to push above and
beyond your risers.

Cougarman

Re: Will Flappers in Silent Choice Lower Y-Pipe let water in the motor if broke?
 

My theory is that i pulled the boat off plane with the drive still trimmed up a bit, leaving the opening exposed under the drive at the gimble. Then when i shut the motor down, and put it in reverse with the other motor.....that forced the water up there past the broken flapper. The other side of the "Y" pipe flapper is in-tact and i think it did it's job.

Rick, this is the other other motor.

Re: Will Flappers in Silent Choice Lower Y-Pipe let water in the motor if broke?
 

I'm thinking that i phucked up by putting it in reverse to clear the bag of the other drive......then tore the top end down for nothing. Heads are going out tommorow to be checked.

Re: Will Flappers in Silent Choice Lower Y-Pipe let water in the motor if broke?
 

Join Date: Oct 2000
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Re: Will Flappers in Silent Choice Lower Y-Pipe let water in the motor if broke?

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I'm thinking that i phucked up by putting it in reverse to clear the bag of the other drive......then tore the top end down for nothing. Heads are going out tommorow to be checked.

THATS WHAT HAPPENS WHEN YOU OVER SERVE YOUR SELF AND LISTEN TO BL NICK
LISTEN TO BL TOM HE KNOWS ....REMEMBER NEED MORE INDIANS NOT SO MANY CHIEFS

Re: Will Flappers in Silent Choice Lower Y-Pipe let water in the motor if broke?
 

Yo Tom. Call me at the office. I left my Nextel home this morning.

Re: Will Flappers in Silent Choice Lower Y-Pipe let water in the motor if broke?
 

Anyone know where i can get a new flapper ?

Re: Will Flappers in Silent Choice Lower Y-Pipe let water in the motor if broke?
 

hi-perf
I would also check the lower Y pipe for the missing flapper. It might be blocking the exhaust, causing the water to build up in the exhaust.

Re: Will Flappers in Silent Choice Lower Y-Pipe let water in the motor if broke?
 

I had the same thing happen.
it is not reversion.
What is happening is the broken flappers get stuck at the bottom of the Y pipe and block the exhaust and water from getting out and it backs up into the engine.
I replaced the flappers and when they broke again it did it again.
I wouldn't even replace them - I don't run any on my boat and I have a very radical cam.
Unless you back up into waves you shouldn't have to worry.