Engine stalls when you introduce water.

[Jdip83]

Looking at a new boat
Has a Merc 120 2.5L
Motor runs and drive is in good shape
Compression is 115
But once you try to run water in the inlet and the motor stalls
You look in the carb thru the butterfly and you see water.

Have any idea what the problem could be.


Boat was last in the water in June and this is why he's selling it.

 

[Exotic4x4]

Re: Engine stalls when you introduce water.

Looking at a new boat
Has a Merc 120 2.5L
Motor runs and drive is in good shape
Compression is 115
But once you try to run water in the inlet and the motor stalls
You look in the carb thru the butterfly and you see water.

Have any idea what the problem could be.


Boat was last in the water in June and this is why he's selling it.

Manifold gasket leaky???

 

[achris]

Re: Engine stalls when you introduce water.

Manifold gasket leaky???

Or the manifold (or elbow) is corroded through...

 

[Don S]

Re: Engine stalls when you introduce water.

Compression is 115

With that kind of compression, it's not worth it to begin with, not counting your water problem.

 

[thumpar]

Re: Engine stalls when you introduce water.

Were are you finding these boats or is it the same one? Even if it is free it is overpriced. The 120 is old. I have one but mine is in great shape. If anything happened that was major I would probably try to find a 3.0 cheap or dump it.

 

[Jdip83]

No idea different boat

Realized mine need way to much

So guy wants to sell it near me and it runs just when u hook up a the flush it dies

The drive rebuilt last December has paperwork
Floor rebuilt 2 yrs ago has paperwork

Seams to run well but just not with a flush connected

So... Ya

 

[79Merc80]

Re: Engine stalls when you introduce water.

Why is it being started without water hooked up to the outdrive in the first place????

 

[Jdip83]

Re: Engine stalls when you introduce water.

Which manifold gasket is it?

When searching for Merc 2.5 the only thing I can find is exhaust manifold gasket. But I was told that it's the Intake manifold gasket.

Sites where I can find would be great.
Could I get it at Napa auto parts or Autozone?

 

[achris]

Re: Engine stalls when you introduce water.

'The manifold' is a combine intake and exhaust, so 'the gasket' is both intake and exhaust. Try to use marine parts on boat engines. Using auto parts is the quickest way to either a premature failure or an explosion.... Yes, I know they are more expensive and LOOK the same as a car part but thy aren't.

 

[Jdip83]

Re: Engine stalls when you introduce water.

Checking the compression before I bought the new boat
the compression was 130 to 135 in all cylinders
just a little update
Asked the guy where he got 110 and 115 and we tryed his tester and got 120 and we tried mine and got 130's
so I was happy

 

[Jdip83]

Re: Engine stalls when you introduce water.

'Try to use marine parts on boat engines. Using auto parts is the quickest way to either a premature failure or an explosion.... Yes, I know they are more expensive and LOOK the same as a car part but thy aren't.

I would only use marine parts Im not that much of a cheap skate.
But Searching NAPA's site they do have marine parts
but I would buy online if I could find a reliable and trustable site.

 

[Jdip83]

Re: Engine stalls when you introduce water.

'The manifold' is a combine intake and exhaust, so 'the gasket' is both intake and exhaust.

Thank you
Now I want to get a exhaust manifold gasket
Correct.

Now do I want the set or do I want just the one.

 

[achris]

Re: Engine stalls when you introduce water.

Thank you
Now I want to get a exhaust manifold gasket
Correct.

Now do I want the set or do I want just the one.

There is only one manifold gasket. Have a look at a picture of the manifold. It is both manifolds cast as one, so the gasket is for both intake and exhaust ports.

If you have the manifold off, you will also need the exhaust elbow gasket. By the sound of things you are not using a service manual, correct?

 

[thumpar]

Re: Engine stalls when you introduce water.

Napa has a good selection of Marine parts in their store. Everything that I have every needed has been in store or at a warehouse within a days delivery time. That gasket is the same on the 120 and 140 so should be somewhat common.

 

[Jdip83]

Re: Engine stalls when you introduce water.

If you have the manifold off, you will also need the exhaust elbow gasket. By the sound of things you are not using a service manual, correct?

I am using the PDF version

its 975 pages but there isn't any clear info on the manifold gasket

That is what I meant by the set. the Gasket sets Ive seen come with an elbow

If you look on the Iboats page for gasket set
it comes with a butt load of gaskets and that's also what I meant.
http://www.iboats.com/Mallory-Exh-M...6110749--**********.021388009--view_id.364389

http://www.iboats.com/Exhaust-Manif...6110749--**********.021388009--view_id.173138
I haven't taken it apart yet
that is why I ask first so I don't make a mistake.

 

[achris]

Re: Engine stalls when you introduce water.

I am I am using the PDF version ...

Of what? Seloc or the genuine manual?

 

[Jdip83]

Re: Engine stalls when you introduce water.

Of what? Seloc or the genuine manual?

As everyone else has stated you need to do some homework, everyone here is willing to help but if this is your first boat you got a hell of a learning curve ahead of you. Here download this: https://docs.google.com/open?id=0B4XV6tt7Q0P-OWEwYjgyZmEtNjI2ZS00NDEzLThmYTUtMTgyMmE0OGY2Y2Ux it's manual #1 which applies to you. Here is also the all engines 74-78 which may contain a few additional items you may need.

https://docs.google.com/open?id=0B1TAvwZ3TjhfOTI5OTMyZTMtNDNkZi00MDAyLWE5MTYtMTI5N2MyNDM3NjZm These are from google docs....it's safe.

This is from a diffrent thread I asked about and this guy gave this to me
so this is all I have been going off of
should I just spend the 39$ and buy the book

 

[starsnstripers]

Re: Engine stalls when you introduce water.

Exhaust manifold to head gasket- 27-52546 Elbow to manifold gasket- 27-39915 You can cross these Merc#s to Sierra marine parts from Napa. I'm seeing different part #s for the 140. If you go into the adults only section in this forum you can see the correct pdf manual you need. Also as stated you might want to check your riser/elbow and manifold for rot through. These are noted for rusting at the gasket area where the elbow meets the manifold. Take it apart inspect clean to the shiny metal replace gasket as well as the Manifold to engine gasket replacement.

 

[starsnstripers]

Re: Engine stalls when you introduce water.

The Sierra/napa #s for the manifold gasket is 18-2896 the elbow to manifold is 19-2919

 

[achris]

Re: Engine stalls when you introduce water.

This is from a diffrent thread I asked about and this guy gave this to me
so this is all I have been going off of
should I just spend the 39$ and buy the book

That's the right manual. No need to buy anything else.........