Helping Out a Friend - Merc 3.0

[M.A.CCruiser]

Good Morning all,

I have a friend who recently acquired a 19 foot Stingray Cuddy with a Mercruiser 3.0 4 cyl. Short story - he bought it from a boat dealer/mechanic in the Sarasota area (Max Marine - you'll see below why i'll tell every person to avoid them in the future) It had a recently installed brand new engine when he bought it. On his second trip out it threw a rod through the bottom of the engine. So obviously something installed incorrectly right? Well he takes it back pleads his case, and ends up getting the 3 month run around on getting the engine replaced (he ended up having to foot some of the bill - but not all) When he gets it back it is not running quite right - but considering the lack of trust for that mechanics he doesn't want to take it back again. So, we're operating now under the assumption that mechanically speaking it should be in "working order" but that they didn't bother getting it tuned in right. And, they obviously had no issues cutting corners (as you'll see below along with a few other items I noticed) So I spoke to him this weekend and I told him how great you guys are on here - so we turn to your infinite wisdom and request assistance.

Now i've been working on my 5.7, so I can draw a few conclusions as to some things we need to get done. But i told him i don't see any point in addressing his acceleration issues and other fine tuning until we make sure everything is hooked up properly. For all we know, this could resolve a portion of what's going on. So lets start there.

You'll see in the attached picture I've drawn a few arrows.




RED ARROW: The red arrow is the top of the valve cover. On my 5.7 there is a tube that runs from here into the flame arrestor to recirculate the "smoke" from the crank case. His has no hose, nor a connection on the flame arrestor to attach one. What could happen here

YELLOW ARROW: What goes here? is this were a hose from the crankcase should go? IS there a part number?

BLUE ARROW: This to me could either be a vacuum line, or is this were that yellow hose should go from the fuel pump in case of diaphragm failure? There is no hose attached to the fuel pump




The only place i could find the serial number was here


The information plate is unreadable


Also, one last question - where should these 3.0's idle? right now he's at about 900 - which seemed high to me.

Again, he's having multiple issues, hard to start sometimes (flooding), acceleration not there, not passing 2800 rpm under load, gauges and sending units not hooked up, etc - so i'll probably have more questions going forward.

As always, you guys are awesome! thank you in advance for all of your help!

 

[Bondo]

Ayuh,... The ports on the carb appear to be for a stove choke, but it's got an electric choke,....

The thing on the shift plate ain't a vent for the valve cover, unless it's hidden under there, but I can't see so in yer picture, it's taken to close,....

 

[Rick Stephens]

If you go straight behind the yellow arrow, about an inch, inch and a half, you should see where the plastic hose from the fuel pump goes. If the diaphragm in the pump goes out then fuel will dump into the carb through that hose instead of in the bilge where it WILL blow you up.

The connectors where the yellow and the blue arrow points at is not used in this configuration.

The red arrow appears to be the valve cover vent hose location. On my 3.0L that has a rubber hose that ends at the outside of the flame arrestor. Hard to tell for sure though. If that pipe is open to the inside of the valve cover then there should be a fitting on the flame arrestor for the hose to connect up and draw oil fumes back into the engine to be burned.

 

[M.A.CCruiser]

sorry for the pictures - i had him take them for me - so i couldn't control the quality. Good to know those ports aren't used - that eliminates an issue.

Thank you for the location on the fuel pump fail-safe - we'll get that hooked up ASAP. He's also got a fuel leak at the fuel level sender in the tank - so we've got a few fuel issues to work out before i allow him to start it with me near it again.

Boat's running... i'm checking things... *sniff sniff* "i smell some fuel..."

"Oh yah, my fuel sender is leaking a bit there... not too much though."

"Shut Off The Boat NOW... are you trying to kill me?"

Boat also has installed an after-market F/W separator attached to the transom using what appeared at first glance to be non fuel rated line. so that'll be getting taken out of there soon as well.

I almost feel bad for the guy.

 

[M.A.CCruiser]

Ok - lets let the party continue on this:

Last night we took the boat out to see if we solved the lack of RPM issue by replacing all of the fuel filters on the boat. Considering this is what his fuel pump filter looked like:



I was pretty confident we would be able to get up and moving.

Launch the boat, fires right up - we're pretty confident. It wasn't warmed up yet so we eased our way up on the throttle - worked it up to about 4k RPM - Success. Pushed it a bit further - 4200 - 4400 awesome. But then we start hearing a very loud almost banging sound from under the engine cover. We pull back to idle, and I open the cover and instantly i can tell it's an exhaust leak. I run my hands around the exhaust manifold and i can feel the exhaust "puffing" out from under the manifold and a little on-top around the middle of the manifold (what assume is the 2-3 cyl) I checked to make sure all the manifold bolts were tight (they were) and I took a look at the riser/elbow gasket and can see that the POS that "rebuilt" the engine used cheap paper gaskets there - so I would say it's a safe assumption cheap paper gaskets were used on the manifold too. I tell my friend that it looks like at minimum he blew his exhaust manifold gasket - hopefully there is not a bigger issue (head gasket?) at play.

We idle it back in (actually running pretty well considering half of the exhaust is just blowing into the engine compartment) and tie up at the ramp to start some other inspections.

Here is where I request the help of you amazing people out there

I can tell we've got a Frankenstein engine here. The timing listed on the valve cover is 6 def BTDC


The timing listed on the Flame arrestor is 1 deg BTDC (special timing required)


One would assume that the valve cover would be right, flame arrestors are pretty easy to swap. But, we have no way of knowing what gasket set to get, what manifolds are on there, what the timing should be, and all sorts of other fun and exciting stuff.

Considering this jackass just added washers to the elbow bolts to make them fit rather than get the right bolts - I don't want to assume anything


So i took a top down shot of the engine, and hoped you can help me identify what is in there. - and yes that is a bent paper-clip holding down one of the throttle cables



Thank you all again for your help - I figure its best to keep one thread going regarding the work on this - but if the MODs and experts feel a different thread for each issue would be better I can do that as well.

still to come: hooking up temp sender - Trim sender/limiter wires cut at the unit - Idle adjustment (haha yah) and what will probably a very fun job of "Name That Wire"

 

[thumpar]

What kind of ignition does it have? Also on that engine the fuel line should be solid from the pump to carb. It looks like it is missing the clean line that is a safety item that goes from the pump to the carb in case of a ruptured diaphragm.

 

[M.A.CCruiser]

he said it has a points style distributor.

and yes it is missing the sight tube from the fuel-pump. that'll be replaced on Sunday along with the manifold gasket

 

[thumpar]

I would go with the valve cover timing. That flame arrestor cover is probably from an engine with electronic ignition of some type.

 

[Rick Stephens]

I would go with the valve cover timing. That flame arrestor cover is probably from an engine with electronic ignition of some type.

Agreed with thump on the timing - the old sticker even states point gap and dwell.

And I believe you can match up the manifold gaskets based on whether you have the open end or the closed end manifold. Looks like yours is the open end. Good time to inspect the manifold thoroughly, so get all the gaskets and take it down all the way.

 

[Bondo]

Ayuh,.... I agree with Thumper, 'n Rick,.... Looks like it matches the valve cover, 'n not the flame arrester cover,.....

 

[M.A.CCruiser]

we were able to match up the manifold gasket - but after the install there was still the same exhaust leak from around the manifold. Headgasket?

 

[Rick Stephens]

Squirt it with soapy water if you can't tell. Did the manifold look in perfect condition? I would expect an old rusted or cracked manifold to be the cause as much as a head gasket. Head gaskets are pretty robust on that old engine unless overheated.

 

[thumpar]

You could do a leakdown test to see if it is the headgasket.