Only goes 20 MPH

Honest Tony

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I lost my rubber inpeller on my 2002 Ebbtide 350 Mag MPI. boat got to 215 degrees.
I replaced it and took it out boat runs fine but will not go over 20 mph. So I did a compression test and all good 155 - 165. HELP
 

Scott Danforth

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Did you check the burned up rubber bits in the exhaust? Flappers? Exhaust hoses?
 

Honest Tony

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I lost my rubber inpeller on my 2002 Ebbtide 350 Mag MPI. boat got to 215 degrees.
I replaced it and took it out boat runs fine but will not go over 20 mph. So I did a compression test and all good 155 - 165. HELP
No I did not a few went out exhaust after I let it cool off and got towed in I fired it to put on trailer. So I need to pull hoses off and clean out?
 

Scott Danforth

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You will most likely find the insides of the rubber hoses burnt and blocking flow.

The shutters may have dropped to the bottom of the Y-pipe and are blocking flow
 

Scott Danforth

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You need to check the hoses.

The flappers are exhaust check valves that prevent water coming back up the exhaust when you cut throttle. They are at the top of the Y-pipe.

Look up the parts based on your serial number
 

alldodge

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I lost my rubber inpeller on my 2002 Ebbtide 350 Mag MPI. boat got to 215 degrees.
I replaced it and took it out boat runs fine but will not go over 20 mph. So I did a compression test and all good 155 - 165. HELP
At 215 something would have changed.
A 155 - 165 compression test "if" accurate means your gauges is a bit off or your tossing info found on the internet

Put a scanner on the motor and see if there are any codes
 

Honest Tony

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How do you hook up a scanner to a boat? I have 3 scanners but they all have the OBll plug in. I changed the oil & filter put new spark plugs cap and rotor on today. I am going to pull the exhaust in the morning and clean it then go test it. I am only 20 minutes from the lake.
THANK YOU ALL FOR YOUR HELP.
 

Scott Danforth

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How do you hook up a scanner to a boat? I have 3 scanners but they all have the OBll plug in. I changed the oil & filter put new spark plugs cap and rotor on today. I am going to pull the exhaust in the morning and clean it then go test it. I am only 20 minutes from the lake.
THANK YOU ALL FOR YOUR HELP.
you have to buy Rinda software and their cable for marine. none of your OBD scanners will work. https://www.rinda.com/marine/marine.htm
 

dingbat

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you have to buy Rinda software and their cable for marine. none of your OBD scanners will work. https://www.rinda.com/marine/marine.htm
Ugh...... CAN and OBD2 are well documented and published SAE and ISO protocols and message structures.

Unless the engine manufacturer developed and replaced the two with proprietary protocols and shared with Rinda this is BS.

All you're buying is scan request and logging analyzer formatted specific to the target market, ie marine engine repair

A generic code reader will have no problem capturing the data up to the scanners current revision level.
 

Scott Danforth

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ok, so you can make an adapter to go from the Automotive OBD connector to the 6-pin marine data link connect, and if you have the address mapping, you may be able to see many of the channels, however the marine ECM is remapped from automotive and they do not use the same addresses. Just like you cant plug a generic OBD reader into a Cummins J1939 diagnostic port.
 

Honest Tony

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I took the top of exhaust manifolds off the 4 bolts on top a removed them
they looked good. Looks like a tough chore to take the next ones off that go where the Y connect so I am going to clean out vacuum and size down the hose and try to vacuum down to the Y tube and see if anything comes out.
WHER IS FASTEST PLACE TO GET NEW GASGETS?
 

Scott Danforth

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You have to remove the down elbows to get to the flappers to inspect. Not even a 300hp vacuum cleaner would help

Your local dealer will have gaskets in stock
 

QBhoy

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Hi. Tell us more about what exactly is happening. Is the engine revving up the rpms well, when in gear…but speed is low and not corresponding to previous behaviour? Or are you struggling for rpms too ? If it’s the former…could you have melted your coupler ? Does it feel like something is slipping ? Or is she just lacking and bogging weak feeling ?
What’s the oil looking like ? Definitely no water ingress causing a false or high compression result ? No melted gaskets or HT leads ? Or similar ? Distributor cap isn’t a casualty perhaps?
 

Honest Tony

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Hi. Tell us more about what exactly is happening. Is the engine revving up the rpms well, when in gear…but speed is low and not corresponding to previous behaviour? Or are you struggling for rpms too ? If it’s the former…could you have melted your coupler ? Does it feel like something is slipping ? Or is she just lacking and bogging weak feeling ?
What’s the oil looking like ? Definitely no water ingress causing a false or high compression result ? No melted gaskets or HT leads ? Or similar ? Distributor cap isn’t a casualty perhaps?
The boat runs fine with the ear muffs (waterHose) on revs up but in the water does not miss just will not go. I replaced the dist cap / rotor/ plugs/ changed oil / But have not put back in the lake since this was done. New gaskets should be here Monday for exhaust. I cleaned exhaust but just to Y pipe don't want to pull that big hose that feeds exhaust threw Brovo 3. What a stupid disign sending exhaust threw the outdrive why not threw the transom
 

alldodge

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

Honest Tony

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Aug 9, 2023
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Boat is a 2002 Ebbtide Mystique 2400 with only 230 hours. I have owned it for 4 years.
 

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