Only goes 20 MPH

[Honest Tony]

Replace exhaust bellows with a exhaust tube, much less restriction and easy to replace without pulling drive

Can you send me a picture of that not sure what you are taking about..
Appreciate the help Guys. Thank You
I wrench on my own cars just new to Boats. 1941 Pro Street Willys Coupe Blown 383 / 1971 GMC Jimmy Pro Street Blown 350 /1999 Tahoe total custom. Summer driver 2012 CTSV 620 HP Sedan

 

[jimmbo]

Toss away 98% of what you know about Auto/Truck Engines, if you want to have any Success working on a Marine Engine

 

[Honest Tony]

Can you send me a picture of that not sure what you are taking about..
Appreciate the help Guys. Thank You
I wrench on my own cars just new to Boats. 1941 Pro Street Willys Coupe Blown 383 / 1971 GMC Jimmy Pro Street Blown 350 /1999 Tahoe total custom. Summer driver 2012 CTSV 620 HP Sedan

I looked on You Tube but all of them are replacing with rubber tube is Exhaust tube just like the stock one?

 

[alldodge]

Tube
https://www.ebay.com/itm/323417826586?hash=item4b4d34651a:g:XOkAAOSw~BNch1Q7

 

[flashback]

A service manual is your friend, so you see how the machine works.

 

[QBhoy]

Hi. Reading this on my phone. Apologies for the ignorance. But you mind telling me again what exactly is the issue. Maybe we have moved on from the original post detail. No doubt. Can I ask a couple of things ?
So from the response you gave me earlier there….have you not actually had the boat in the water since the event ? Or have you…and it’s not going over 20 mph ? Just so I’m clear on things. I read your response to me there as maybe you haven’t been back to the water since.
Also…did she previously manage to pick water up from the muffs you have when on the trailer ? Some muffs out there aren’t able to fit properly to enable these bravo (and some VP) to pick water up easily or at all. Being the case, have you tried sticking the hose directly into the suction side of the engine driven pump ? Thus ruling out the above or any issues with the integrity of the pipe work and fittings from the drive, PS cooler (if in line there) etc.
other wise and either way above…you could perhaps crack open the exhaust manifold drains to prove the presence of flowing water upstream or previous to any flappers or restrictions suspected beyond the manifolds.

 

[Scott Danforth]

Hi. Reading this on my phone. Apologies for the ignorance. But you mind telling me again what exactly is the issue.

Per post #1

He overheated due to failed impeller and now the motor idles ok, however the motor won't rev under load

 

[QBhoy]

Per post #1

He overheated due to failed impeller and now the motor idles ok, however the motor won't rev under load

That’s what I thought Scott. But my confused state, perhaps came from the reply to my post earlier, perhaps suggesting that the boat hasn’t been in the water since. My conflicting thoughts came from the suggestion that it wasn’t going over 20mph in the first post…making me assume it has been water tested since. Maybe just me being silly.
Must admit though, left me wondering if it was perhaps meaning that it would t go above certain rpms since and when on the trailer. I’m sure it will be known to the fella, that mpi of a certain age onwards (most of them) won’t allow you to rev past around 2000/2500 rpm in neutral, when perhaps trying such a thing on the trailer.
Anyway…points around proving water flow I’ve mentioned above..might still be handy otherwise

 

[Honest Tony]

Hi. Reading this on my phone. Apologies for the ignorance. But you mind telling me again what exactly is the issue. Maybe we have moved on from the original post detail. No doubt. Can I ask a couple of things ?
So from the response you gave me earlier there….have you not actually had the boat in the water since the event ? Or have you…and it’s not going over 20 mph ? Just so I’m clear on things. I read your response to me there as maybe you haven’t been back to the water since.
Also…did she previously manage to pick water up from the muffs you have when on the trailer ? Some muffs out there aren’t able to fit properly to enable these bravo (and some VP) to pick water up easily or at all. Being the case, have you tried sticking the hose directly into the suction side of the engine driven pump ? Thus ruling out the above or any issues with the integrity of the pipe work and fittings from the drive, PS cooler (if in line there) etc.
other wise and either way above…you could perhaps crack open the exhaust manifold drains to prove the presence of flowing water upstream or previous to any flappers or restrictions suspected beyond the manifolds.

I pulled the elbows and both the flappers are toast gone so I pulled the tube that connects the exhaust to the outdrive (Bellow I guess) and one of the flappers was in the tube going back to the motor and the other one was stuck up in the outdrive finally got it out with a piece of coat hanger.
Both of them still had rubber around them. I pluged up the outdrive side with a rag and blew out both exhaust with air hose just small pieces came out. So I will order new flappers and go test it. Thanks againall.

 

[Scott Danforth]

Inspect the insides of the rubber hoses

When you ran out of water, your exhaust temp went from 210F (water and exhaust) to 1100+ ( exhaust only)

The rubber hoses are good to 250 then they burn

 

[Honest Tony]

That’s what I thought Scott. But my confused state, perhaps came from the reply to my post earlier, perhaps suggesting that the boat hasn’t been in the water since. My conflicting thoughts came from the suggestion that it wasn’t going over 20mph in the first post…making me assume it has been water tested since. Maybe just me being silly.
Must admit though, left me wondering if it was perhaps meaning that it would t go above certain rpms since and when on the trailer. I’m sure it will be known to the fella, that mpi of a certain age onwards (most of them) won’t allow you to rev past around 2000/2500 rpm in neutral, when perhaps trying such a thing on the trailer.
Anyway…points around proving water flow I’ve mentioned above..might still be handy otherwise

I am sorry but/ After I replaced the impeller I did put it in the water and it did not heat up but would not go over 20-25 mph so thats when I replaced dis cap rotor / sparks plugs and oil change, and has not been back in water since this was done. Because now fixing exhaust hope to test it Wednesday
paid for 2 day shipping on shutters, lake is only 20 minutes from my house.

 

[Honest Tony]

Also that diagram of exhaust only shows 1 Flapper my boat has 2 one on each side.

 

[jimmbo]

This is what one Flapper looks like. I have never seen 2 per side

 

[Scott Danforth]

and each of the flappers has two leafs. make sure to get all the bits out of the Y-pipe. most of the time, you have to pull the drive to get them out.

 

[Honest Tony]

This is what one Flapper looks like. I have never seen 2 per side
View attachment 387445

I have 1 on each side 2 total

 

[Scott Danforth]

I have 1 on each side 2 total

Each flapper has 2 leafs

 

[Lpgc]

If you had a broken flapper or bits off a broken flapper constricting the exhaust, could the flow of water cooling the exhaust back up all the way to the engine causing water to enter engine cylinders through exhaust ports?

 

[Scott Danforth]

If you had a broken flapper or bits off a broken flapper constricting the exhaust, could the flow of water cooling the exhaust back up all the way to the engine causing water to enter engine cylinders through exhaust ports?

Most likely not. Just restricts exhaust flow enough to choke the motor

 

[Honest Tony]

Most likely not. Just restricts exhaust flow enough to choke the motor

 

[Honest Tony]

FIXED IT. I took off the exhaust risers down to the Y Pipe both shutters were toast. So I took off the exhaust Below off and looked into the whole system with my Borescope and found all the pieces and used air to blow them to where I could get them with a piece of wire. But it back together with new gaskets, shutters and new Below. Tested the boat runs great. THANKS FOR ALL YOUR HELP.