Help! Bought a 1993 Four Winns W/ 5.0 OMC Cobra Motor and Drive - Losing power after crusing

[Lou C]

What's the best way to do a shift adjustment, there is a slight grind when first going into gear. Nothing while operating but definitely there upon engagement.

there's no short answer to this if you want it right
it involves pulling the drive and disconnecting the shift cable at both ends, to check drag (no more than 2.5 lbs)
also you measure the height of the shift rod on the lower unit, that is an important basic adjustment but when it's right it never changes.
do a search on my user name I have posted it a few times, you also should get some special OMC tools to make sure it's right
once it's right, it will shift with 2 fingers, in and out of gear, and not grind or clunk.
with a dog clutch, grinding is often caused by shifting too slow, or because of sticky cables that don't move the dog clutch fast enough for a nice THUNK instead of a griiiinnnddd CLUNK.

 

[cameron92]

Also just found this. Oil was fine when I bought the boat. I'm ready to bring this back to the guys house.

 

[Lou C]

sorry to see that
did he not winterize it?
did he give you a bill of sale? what did he write on it?
old boats are headaches, anyone here can tell you that

if I ever buy another boat, it will be no more than 5 years old and OUTBOARD powered.
old sterndrive boats are a headache that I have learned to live with but given the choice, I'd always choose a late model 4 stroke outboard.

 

[cameron92]

sorry to see that
did he not winterize it?
did he give you a bill of sale? what did he write on it?
old boats are headaches, anyone here can tell you that

if I ever buy another boat, it will be no more than 5 years old and OUTBOARD powered.
old sterndrive boats are a headache that I have learned to live with but given the choice, I'd always choose a late model 4 stroke outboard.

Just found out he changed the tachometer too. This is my first boat. 5k down the drain. The tach is from a 2007. Said it had 685 hours.

F me.

 

[Lou C]

small claims court?
well we all get taken at least once I guess
mine had a rotted deck I didn't spot, wound up taking a LOT of work to put right but that's 20 years ago and it's still solid now!
Live and learn
never buy an old boat
late model boat 5 years old or newer
if you're in freshwater, I'd buy an aluminum boat with an outboard.

 

[Lpgc]

Ya there's a little microswitch I forget the name of it but when I press it the rpms drop

That's not what I meant, I meant something like a hall effect sensor to detect engine rpm (crank sensor) and a similar hall effect sensor to detect drive rpm.

I vey much doubt there'll be a speed sensor in the drive though.

 

[Scott Danforth]

Im going to state the obvious. The Ford EFI and ignition system on the boat are no longer supported. the tach appears to be erratic and could be failing itself, or is getting multiple firings from a failing EFI ignition

disconnect the grey tach wire and use a shop tach to verify the motor RPM's

draw a line across the prop and the hub to check for spinning prop hub
pull the drive and inspect the coupling

 

[cameron92]

Im going to state the obvious. The Ford EFI and ignition system on the boat are no longer supported. the tach appears to be erratic and could be failing itself, or is getting multiple firings from a failing EFI ignition

disconnect the grey tach wire and use a shop tach to verify the motor RPM's

draw a line across the prop and the hub to check for spinning prop hub
pull the drive and inspect the coupling

Is it worth all that with water in the oil pan after only a 30 min total boat ride?

 

[Scott Danforth]

Is it worth all that with water in the oil pan after only a 30 min total boat ride?

up to you. the water in the pan is most likely a cracked exhaust manifold. you have to test and check and troubleshoot prior to firing any parts cannon

 

[cameron92]

up to you. the water in the pan is most likely a cracked exhaust manifold. you have to test and check and troubleshoot prior to firing any parts cannon

I'm guessing I can just pull the manifolds off and inspect? Sorry I'm very new to this

 

[Scott Danforth]

google acetone testing marine exhaust manifolds

 

[Lou C]

Yes but be VERY CAREFUL with acetone, it's very flammable. I have done it 2x, it's a good test for leaks. Plus you can recapture the acetone and use it to clean stuff (carefully!)
when you get em off, take pix of the exhaust ports on your engine and post em up. They should be grey/black not red and rusty inside!
Here's an old pic of mine, the rust on the cyl head is just moisture trapped under the gasket....these manifolds weren't leaking but were getting clogged so they got replaced. I think I'm up to exhaust system #3 on this boat, that's salt water use.

 

[Scott Danforth]

using Lous pic.

 

[cameron92]

Yes but be VERY CAREFUL with acetone, it's very flammable. I have done it 2x, it's a good test for leaks. Plus you can recapture the acetone and use it to clean stuff (carefully!)
when you get em off, take pix of the exhaust ports on your engine and post em up. They should be grey/black not red and rusty inside!
Here's an old pic of mine, the rust on the cyl head is just moisture trapped under the gasket....these manifolds weren't leaking but were getting clogged so they got replaced. I think I'm up to exhaust system #3 on this boat, that's salt water use.
View attachment 417138View attachment 417138

I'm having a real hard time getting them off is there a good spot to pry at them?

 

[cameron92]

User error. Missed 4 bolts. Can't get it off the studs and I can't get the exhaust out of the rubber. Still working away

 

[cameron92]

One side down

 

[Lou C]

From what we can see, your manifolds and exhaust ports look good.
On mine, that pic was when I had the old OMC batwings, I'll have to take a pic of what the reman heads I installed back in '17 look like, next time I take off the exhaust. I had to pull the exhaust off in '21 to get at the steering actuator and they looked good then. The later 2 piece units might be less prone to pulling water up the exhaust than the old one piece batwings.

I'm not familiar enough with Ford engines to know for sure but they do have water ports on each side of the intake side of the head, and if that gasket leaks, I'd think it would put water in the oil like it does on the GM engines. A well-known problem with the early Vortec engines.

PS next time you have to do battle with the evil exhaust rubber hoses, get some large picks that are made to pull off hoses, but first, heat the rubber just a bit with a heat gun (NOT smoking hot, just like maybe 100-100* or so, use an IR temp gun to monitor), then start prying. Next spray silicone spray in the gap and keep prying it will come but takes a bit of time. When you put them back together a bit of silicone grease may make the next time easier. Silicone grease won't degrade the rubber like regular grease will.

 

[cameron92]

Other side. Will do compression next. Need to figure out how to disable fuel injectors

 

[Scott Danforth]

Other side. Will do compression next. Need to figure out how to disable fuel injectors

dont use the key to turn it over

use a remote start button (jumpers the starter terminal)

 

[cameron92]

Starboard Front to Back
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Port Front to Back
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105