Overheat on 5.0 with SX outdrive

[PaulinSWFL]

PS
I had a bad overheat back in 2013 and while the engine ran fine for the rest of that season & 2 more seasons it blew both head gaskets at the end of the ‘16 season. Had water in the oil and in a cylinder. In the tear down I found that both cyl heads had cracks in the exhaust valve seat areas. So I replaced both heads with reman heads new gaskets and new head bolts. Still running well 4 years later. So when you get yours up & running watch for water in the oil and/or water in the cylinders.

I hope that's not the case here since the block, heads, etc are all new in September.
Such a dumb ass mistake. At least I will never leave that flush cap off/not screwed in correctly again.

 

[Lou C]

Sounds good!

 

[PaulinSWFL]

Lou, I replaced the stat today and that was easy. The one I took out didn't look damaged or anything and seemed functional as far as the spring mechanism, etc. The o-ring was fine, not melted or anything.
It still doesn't start. Found nothing blocking any hoses.

Both batteries test fine. Have them wired in series with a a 1,2, both switch.
Took a few plugs out, they look fine. I don't have a compression gauge.

Since the block and heads are cast iron (302 Ford Mustang engine), the cracked scenario is possible but unlikely from what I read. I hope not anyway.
It cranks fine from what I can tell but doesn't fire.

Now I am limited in my car engine trouble shooting abilities. The carburetor is a newer Holly 2bbl. All cap and plug wires look fine, etc.
I might have to buck up. Boat=BustOutAnotherThousand. Just don't have the tools and or time for a tear down. I do not mind the labor and love to troubleshoot and use my brain.

Any suggestions are always appreciated. Especially since the bride is talkinf about what a great boating day it would have been here in SWFL. She busts them pretty good but can take it too. lol

 

[PaulinSWFL]

did you find the missing parts? if not, start looking.

also, once you smoked the impeller from lack of flow, you also took out the rubber exhaust hoses as your exhaust went from a typical 220F (water and exhaust) to over 950F (just exhaust)

depending on how hot your motor got, you may want to test compression. a good motor will be between 130 psi and 150 psi in all 8 cylinders.

the fact that the motor just "shut off" indicates it got really warm.

stat got replaced today Scott. It made no difference actually. It was easy though. I don't have the gauge to test compression but took a few plugs out to see what they looked like and they were fine. Batteries are fine. Engine seems to crank fine but just doesn't start. It's a 302 Ford which is basically a cast iron Mustang engine.
It's above my skill level now but I am open to suggestions. Thanks.

 

[Lou C]

You’ve got to do more trouble shooting to find out why it doesn’t start. Check for Spark first then check the fuel system

 

[ripjmk]

As you said that when the over heat happened the engine just shut itself down, I would remove the distributor cap and turn the engine over to check that the rotor is still turning. If your engine has the plastic cam drive gear it could have stripped teeth!

 

[Scott Danforth]

As you said that when the over heat happened the engine just shut itself down, I would remove the distributor cap and turn the engine over to check that the rotor is still turning. If your engine has the plastic cam drive gear it could have stripped teeth!

Unless someone installed plastic gears, they are cast iron.

 

[ripjmk]

Unless someone installed plastic gears, they are cast iron.

Back in the 90's I helped a friend change out the stripped phenolic gear in his Ford Bronco 302. So not all 302's had cast iron cam gears.

 

[Lou C]

I think if the cam gear was wearing you'd have heard some odd noises, you had an overheat, and then a no start, so when you crank it are the spark plugs getting voltage? Just use a simple spark tester and check. If not then you get to the next step. One thing, OMC & Volvo used a Prestolite BID electronic ignition system by then, that you can't get parts for. So if the ignition module is bad, you might have to convert it to a Pertonix aftermarket electronic ignition.
BUT...start with spark at the spark plugs, if none check your cap & rotor, ignition coil and module. Might be nice to have a shop manual now, lol.
BUT BUT make sure if that boat has a safety lanyard it is in place! Because if it got jarred loose then the boat will crank and not start.
Then if you have spark and no start, see if the electric fuel pump is powering up and has pressure. Pump the gas while looking in the carb venturi with the choke plate held open do you see 2 streams of gas? If not then that could be it.
You need spark + gas + compression. The last you undoubltly have its the first 2 you need to check. Auto shop 101. Easy stuff.

 

[Scott Danforth]

Back in the 90's I helped a friend change out the stripped phenolic gear in his Ford Bronco 302. So not all 302's had cast iron cam gears.

what does a ford 302 have to do with the GM 305? you are comparing potatoes and cacti

 

[Lou C]

looks like in '95 OMC/Volvo's 5.0 was a Ford....lol....I know they used both GM and Ford engines....I use the old OMC catalog because without the arcane Volvo model number their parts catalog is indeciperable, and between '94 and '98 OMCs and Volvos were the same, same parts #s, painted same color etc.

OMC Stern Drive 1995 5 502APHUB [502APHUB] - Parts Lookup | Crowley Marine

View parts diagrams and shop online for 502APHUB : OMC Stern Drive 1995 5 502APHUB. Offering discount prices on OEM parts for over 50 years. FAST $4.95 shipping available.

www.crowleymarine.com

DISTRIBUTOR - 1996 Stern Drive 5.8 584APNCA | Crowley Marine

View parts diagrams and shop online for DISTRIBUTOR parts, 1996 Stern Drive 5.8 584APNCA. Offering discount prices on OEM parts for over 50 years. FAST $4.95 shipping available.

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second link is to ignition system. Looks like the Prestolite BID system.

FUEL PUMP & FILTER - 1995 Stern Drive 5 502APHUB | Crowley Marine

View parts diagrams and shop online for FUEL PUMP & FILTER parts, 1995 Stern Drive 5 502APHUB. Offering discount prices on OEM parts for over 50 years. FAST $4.95 shipping available.

www.crowleymarine.com

looks like you have a mechanical fuel pump, lucky, and if bad don't have to pay their price just find out which carter marine pump it is.

 

[ripjmk]

what does a ford 302 have to do with the GM 305? you are comparing potatoes and cacti

OP stated it was a Ford 302!

 

[Scott Danforth]

OP stated it was a Ford 302!

I stand corrected on the block and heads

however VP did not source ignition components from Ford. the distributor gear is still cast iron.

 

[ripjmk]

I stand corrected on the block and heads

however VP did not source ignition components from Ford. the distributor gear is still cast iron.

It was the cam drive gear not the distributor gear. I merely mentioned it as it is a very simple check he can do to confirm the rotor it turning.

 

[PaulinSWFL]

I think if the cam gear was wearing you'd have heard some odd noises, you had an overheat, and then a no start, so when you crank it are the spark plugs getting voltage? Just use a simple spark tester and check. If not then you get to the next step. One thing, OMC & Volvo used a Prestolite BID electronic ignition system by then, that you can't get parts for. So if the ignition module is bad, you might have to convert it to a Pertonix aftermarket electronic ignition.
BUT...start with spark at the spark plugs, if none check your cap & rotor, ignition coil and module. Might be nice to have a shop manual now, lol.
BUT BUT make sure if that boat has a safety lanyard it is in place! Because if it got jarred loose then the boat will crank and not start.
Then if you have spark and no start, see if the electric fuel pump is powering up and has pressure. Pump the gas while looking in the carb venturi with the choke plate held open do you see 2 streams of gas? If not then that could be it.
You need spark + gas + compression. The last you undoubltly have its the first 2 you need to check. Auto shop 101. Easy stuff.

Looks like the sudden shutdown caused water to back up into the exhaust via the huge wake left from going 30 to shut down because I see water in the oil and some water blew out of plug 4 after removing the plug and cranking it. Not much but some. Plug wasn't wet and looked fine.
Not looking good.
I took it to a local marine mechanic (Englewood, FL) who works on just old school stuff like this 302 Ford in this boat. A Volvo Penta out-drive guy too. I will dump some money into it if need be because I work too much to spend all my time on the boat repairs and it's a sweet boat. Just ask the wife! lol. It is.
I love to learn and fix these kind of things and have mechanical ability but my specialty is electronics and particularly any and all things fiber optic related. Lack of tools like gauges, etc. Whats another 30hrs overtime in work? UGH!
All the advice and help is invaluable and I will keep this going to let y'all know what this costs. Especially the parts money with the inflation on everything and availability or lack of availability. Sierra stuff seems to be available everywhere. I gave him the ok to use after market stuff.
Thanks to all of you. I will get back soon.

 

[Lou C]

Did it hydro-lock? If not it may not be that bad; when mine had water in a cyl it wasn’t enough to hydro-lock it so I was able to do the repairs needed without having to get into the short block. Doesn’t sound like it from what you’re saying.

 

[PaulinSWFL]

Did it hydro-lock? If not it may not be that bad; when mine had water in a cyl it wasn’t enough to hydro-lock it so I was able to do the repairs needed without having to get into the short block. Doesn’t sound like it from what you’re saying.

 

[PaulinSWFL]

I guess it did not hydro lock only because it cranks? My understanding of hydro lock is not solid. Can you help me understand it better? any advice is appreciated.

 

[Lou C]

If it hydro-locked when you want to start it; it would not crank normally; either one solid CLUNK then nothing or really slow erratic cranking. The problem with Hydro locking is it can cause severe engine damage like bent connecting rods…..

 

[Lou C]

Air compresses water does not