Mercruiser 140 Rochester 2 Barrel Carb pics

[italianstal27]

Hi all!

my buddy and I are in the process of restoring our Holiday i/o 18'.

our carb "looks" like it's in pretty bad shape, but was hoping pics are enough for you guys to estimate if it's corroded beyond repair, or if replacing the gaskets might help it out!
Link to our rebuild page below!
http://forums.iboats.com/forum/boat-repair-and-restoration/boat-restoration-building-and-hull-repair/10343417-76-holiday-i-o-18-fishing-rebuild-pic-heavy/page1
Thanks!

 

[Bt Doctur]

You wont know untill you take it completely apart but I`d say its been under water and shot

 

[italianstal27]

Still runs! But our engine won't run below 1700 RPM without stalling. We've tried adjusting the idle screws

 

[Bondo]

Ayuh,.... It's the Insides that matter, but that looks like junk to Me,....

 

[jimmbo]

I'm surprised the throttle shaft turned. It looks bad, but it won't hurt to take it apart and see if it can be cleaned up.

 

[italianstal27]

Is the corrosion on the outside a symptom of it being in a doghouse that was saturated with water? I've really never seen anything like it. The engine exterior is fairly rusted. Could that have caused the chemical reaction on the exterior of the carb? I'll take pics of the interior tomorrow. I took it apart last night

 

[Scott Danforth]

that carb is junk. anything that was plated is now rusty or corroded.

if there was that much water in the bilge, you should check the stringers and bulkheads for rot

 

[fishrdan]

With that much corrosion outside, I'd expect the same in the tiny idle passages, not good. Once it's torn down, soak it in PineSol for 24hrs and see how it comes out.

2 things I'd be worried about: plugged idle passages, pitted accelerator pump bore. There's probably more...

 

[GA_Boater]

This was a gasketed surface to the intake. Ya think it won't leak air? That's why it idles so high. Tear it apart, the insides can't be much better,

 

[italianstal27]

Wyatt tore it down some more last night while I worked on the transom assembly degreasing, here are some pics!




Seems to be cleaning up ok!

At $25 for a rebuild kit, we're strongly considering giving it a shot! O'rileys quoted us at $220 and that's probably not even for a marine grade carb. Ebay is around $280.

We also started tearing into the engine and found water sitting inside the exhaust manifold:


We were super nervous at this point, and started tearing it down some more, end of the day here's what we found:


We may or may not have forgotten to drain the antifreeze before we cracked the head bolts....

Anyone else here accidently end up with antifreeze on the top of their pistons? :facepalm::facepalm:

-John

 

[Scott Danforth]

I would be less worried about antifreeze and more worried about the rest of the motor. that much rust in the exhaust ports is concerning.

the carb is still junk. new carbs are cheap

 

[italianstal27]

The exhaust manifold gasket was in very bad shape, as was the gasket that connected the carb to the valve intake.

We're thinking it's entirely possible that we were sucking in moisture from the cracked gaskets and with storing the boat for 6 months in humid Oregon weather without fogging, that's what caused the rust.

Plausible?

 

[Scott Danforth]

doesnt sound plausible, it sounds like your trying to convince yourself to continue sinking money and time into a junk carb

the rust in the exhaust is from a failed riser gasket or a cracked manifold or riser or the motor was submerged

the carb gasket issue is from the fact that the carb is junk from corrosion or the motor was submerged

Since a rebuild of the 3.0 is about $1500 and a new carb is about $300 and exhaust manifold and riser is about $500, I would be on the lookout of a running 3.0 with the free boat attached to it for about $500 or so and let this one go

you could probably get a 4.3 long tail for about $900 complete and get the holiday moving along quite well.

 

[Brandon5778]

That's about what my carb looked like when we tore into it.. Nasty. We just decided to replace with a new remanufactured one instead of rebuildin for the peace of mind. Cost 288$ with a refunded 80$ core charge..

 

[Bondo]

Ayuh,.... I don't suppose ya did a compression test on that motor, before ya pulled the head off, did ya,..??

That motor has been drinkin' water for awhile,....
The piston tops are steam cleaned,.... they should be covered with carbon build-up,....
So far, I see little that ain't scrap,... that carb is Junk,...

 

[italianstal27]

We got halfway through tearing into it before we realized we forgot to do a compression test. I even bought the gauge for it.

Seems super easy to get short sighted when you're in the middle of tearing stuff apart.




Cleaning in progress...

 

[jimmbo]

Is there a ridge from the piston rings near the top of the cylinders?

Your old carb is in pretty sad shape, you might not get the core charge back

 

[italianstal27]

No rings on the cylinder.

We rubbed the exposed areas down with engine oil 5w-30 but it appears a patine of rust is developing. New plan is to get some paper towels soaked in oil in the cylinder heads to prevent anymore minimal rust from developing.

Called some local marinas for a 140 3L and low an behold they do not make the blocks anymore. So these are now hot commodities. Our game plan is to buy all marine grade gaskets plus a rebuild kit for the carb.

If we can get another 5 years off the carb + 10 years off the engine we'll be in good shape. As soon as the new gaskets are on and rust removed we'll run a pressure test.

The majority of our coin is going into the decking + interior on the rebuild leaving very little for the engine. A rebuilt "ready to drop in replacement" is $5700 from the local marine supply store. Our time is fairly cheap as we're under 30 with no kids and not married... And we feel like we're learning a lot about how engines work. We also don't have room at the house for another parts boat.

Given those limiting factors we are trying to make the best of this situation. New gaskets should help, but the compression test after rebuild will really tell all.

Totally going against the advise of everyone here, but we really do appreciate everyone's input. It's just the cost of a new engine that's holding us back from pulling the trigger right now. If it's OK I'd like to continue updating everyone on our engine progress!

-John

 

[fishrdan]

Since you're pushing forward.... strip carb, soak in PineSol for a 24hrs, brush it off with plastic brushes, spray it off with hot water in the sink, compressed air through all the passages, run a fine wire through all the small passages, spray off again, compressed air.

With all that rust on the engine, sand down where the belts ride on the pulleys and paint the pulleys with Rustoleum. A rusty pulley will shred belts.

Fill the manifold water jacket with "acetone", let it sit and look for leaks (cracks). Get a FelPro marine gasket set, head set, if this is as far as you're tearing it down. Manifold>head and manifold>riser must be the shiny graphite type, not cheap paper type that leak.

Water was in head, so have it rebuilt. Chase all head bolt threads in block with a tap, and check the deck flatness.

Personally, myself, after verifying that the engine runs and isn't junk.... I would replace the starter with an aftermarket high torque permanent magnet type and also swap the alternator. Probably around $100 for both, aftermarket. Spin the water pump and see it it turns smoothly. With an engine that old, all engine accessories are suspect, could last for another 10 years or fail on the first outing.

You're going to need an engine alignment tool to align the engine, $50 off Ebay. Bellows, raw water pump, lower shift cable...

 

[italianstal27]

Bless you.

Excellent advice. We're in the process of pulling the head gasket off the engine block. Taking care to not let it drop into the screw holes. We have rags in the cylinders now to prevent rust from forming. We ordered the $100 set of head gasket + all gaskets for fuel pump etc. All new electrical connections.