New to me 1995 4.3 OMC Cobra in Chris Craft

HT32BSX115

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Would this service bulletin apply to this engine? Its the same parts as the OMC. I'm guessing somebody already removed the "flapper" and left the pin like the bulletin describes.
Google: P-25-1 2 01

You can probably get away without them. Since the pins are still there, it appears that the PO either didn't remove the old ones or didn't follow the instructions in the SB.

Either way, like LouC indicated, you need to ensure that the old ones are not down at the bottom plugging up your y-pipe.
 

Alaboat

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And so the saga continues...Since I was able to start engine the other day with considerable difficulty and ran rough while cold, I decided I would change the plugs yesterday (AC Delco MR43T). When I pulled the plugs, what seemed like water mixed with gas came out. Plugs looked pretty bad but were some Bosch plugs. Plugs were not in very tight and one was only finger tight...wow. So then I pulled distributer cap and it was pretty crusty with yellowish carbon which I scraped off and cleaned up all contacts on both cap and rotor(gonna get new ones). Put all back together and with freshly charged new battery thought it would roar to new life. No go. Engine would not fire or only cough. Continued trying to start and finally ran battery down again. Seems like starter is kicking out without engaging long enough to start. Maybe water in the gas tank? Any thought on next step?
 

steely85

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Well. You could start with finding out if there is a spark issue or if it is a fuel Issue. Test the plugs and check for spark.
second. It shouldn't have water in the fuel due to the water separator. But you could change that. You could also siphen the gas out and put in all new. If you don't want to siphen the gas out yet you could always jut put a hose into a portable gas tank as run it that way.
Third. Double and triple check your firing order and make sure you didn't accidentally re arrange the plug wires on the cap.
4th. I'm not sure on this one but there might be a little wire going to the back of your distributer you can make sure it did not get Unplugged
 

Alaboat

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Well. You could start with finding out if there is a spark issue or if it is a fuel Issue. Test the plugs and check for spark.
second. It shouldn't have water in the fuel due to the water separator. But you could change that. You could also siphen the gas out and put in all new. If you don't want to siphen the gas out yet you could always jut put a hose into a portable gas tank as run it that way.
Third. Double and triple check your firing order and make sure you didn't accidentally re arrange the plug wires on the cap.
4th. I'm not sure on this one but there might be a little wire going to the back of your distributer you can make sure it did not get Unplugged

If the water separator is full of water, wouldn't it allow some water to bypass and get in cylinder? I changed plugs one at a time so don't think there is an issue with crossed wires but I'll check all wires again. I'm gonna pull filter later today and pour out contents in a jar to see if there is water or how much. Also gonna try the portable tank and see what happens. Hate to think about draining tank because I just filled it up. What about adding Seafoam to the gas tank?
 

JJBoatr

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Yes, if the filter is saturated with water it will allow water into your engine. I have had this happen to me in my younger years of boating. I change my Fuel/Water filter every year and keep a spare in the boat during the season. If there is water in your fuel you may be able to see it on the throttle plates inside the carb after pumping the throttle. Water will form small droplets on the plates. Since the PO had a lot of theory's and not a lot of knowledge your problem may also be bad gas. If he didn't treat the fuel and it has gone bad then you have no choice but to get it out of your tank. The 4.3 is a great engine in an I/O and it will run like a watch once you get it some clean fuel to it. All this assuming you have verified good spark.
 

Alaboat

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So I pulled fuel filter and dumped fuel into clear container. Pretty funky looking but very little water. I then pulled fuel supply line at pump and ran some tubing out of bilge drain hole to outside and siphoned a little gas from bottom of tank. Gas look clear and good. I then went and removed the new plugs that I installed yesterday and there was clean water on the plugs...where it water on plugs coming from???
 

Alaboat

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Riser/Manifold gasket.

Care to elaborate? Are you talking about this:
3853412GASKET, Manifold to engine
What would that have to do with water on plugs? Still couldn't get it to start today.
 

bruceb58

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riser/manifold...not manifold engine since there is no water passage there.

Water leaks in when you shut off engine and leaks down into cylinder through open exhaust valve
 
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JJBoatr

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Was there water on all of the plugs? Or just a few of them? Did you change the fuel/water filter or put the the old one back on?
 

Alaboat

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There was water on all of the plugs. When I removed some (seems like ones at front of engine), a little water even trickled out. I just put the old filter back on after draining until my new one gets here.
Oh, another thing that I have noticed when trying to start is that starter does not seem to stay engaged and keeps kicking out. From previous outboard experience, this is what would happen when battery was weak but battery has been fully charged and is new and I recharge after each no start episode. Also, really weird sounds like its banging the flywheel.
 

Alaboat

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So I pulled all the plugs again and bumped over engine multiple time to help pump out water. Then did the same thing using compressed air until I got all the water I could out. I then replaced the riser gaskets on both sides and buttoned everything up. Also took starter off and had it tested and it was fine. Put back on. Tomorrow, I will remove old fuel filter and flush out several times with clean gas, fill it up with gas and reinstall. Then I will hope for the best and proceed to start. I hope with all of you guys help, I have fixed the problem.
 

bruceb58

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Don't ever reuse an old filer. Always get new. Just dumping out a filter will put junk on the outside of the element. Sure way of screwing up your fuel system.
 

Alaboat

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Everything buttoned back up last night and engine fired right up today and running smoothly however starboard exhaust elbow still getting too hot. Could some passages be clogged from previous owners impeller failure? Guess I 'll pull impeller housing to look at condition of impeller. If blades failed, would pieces tend to go through same side as pump? Also running on hose at full pressure, should some water and exhaust exit through prop on idle or all through transom bracket?
EDIT: Went back out to fire up and couldn't get it started. Acting just like it did yesterday. Pulled plug and water on plugs!!!
I'm guessing next stop is REAL mechanic; I'm at my wits end
 
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Alaboat

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bruceb58, instructions that came with gasket said "Notice! Do not use any sealant on the riser gasket". Against my better judgment, I followed those instructions. What is your thoughts on this? Obviously something is very wrong if I'm getting water back on the spark plug side of the engine. Also, would removal of the flapper valves in exhaust "Y" pipe cause issues with running engine on muffs. Mine had flappers at one time but now gone possibly due to the service bulletin. Previous owner advised not to run engine on muffs. I know I am repeating myself on some of this but considering that with the new info.
 
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bruceb58

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For awhile they were saying not to use sealant. I also did not use sealant last time I changed my risers/manifolds.

Do you know if these are OEM manifolds/risers? If they are not, it would be worthwhile checking how flat the mating surfaces are.

You do not need the flappers. They aren't even installed by the factory anymore and Volvo had a service bulletin to leave them out.
 

Alaboat

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For awhile they were saying not to use sealant. I also did not use sealant last time I changed my risers/manifolds.

Do you know if these are OEM manifolds/risers? If they are not, it would be worthwhile checking how flat the mating surfaces are.

You do not need the flappers. They aren't even installed by the factory anymore and Volvo had a service bulletin to leave them out.

Pretty sure everything is original to engine. I lightly block sanded both mating surfaces with 100 grit until uniform and checked flatness. There was no corrosion or other abnormalities present and torqued to 29ft/lbs. as recommended.
 

Alaboat

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So I've called around to see who will work on my engine. Spoke with mechanic at one shop giving some info about issue. He said since I am having water getting into both sides of engine, its not likely a head gasket but more likely an intake issue. Most shops around here experiencing nearly 2 week backlog of work due to boating season just starting. Waiting to hear back from a couple of other shops nearby.
Another thing that I found odd was that instructions that came with the new VP riser gasket said no sealant and torque to 29 ft/lbs whereas the info from service manual says some contradictory info with different torque values. Maybe due to different type of gasket material?? To install:
8. Clean the mating surfaces of the manifold and elbow thoroughly, coat both sides of a new gasket with Gasket Sealing compound and position it onto the manifold flange.
9. Position the elbow on the manifold so the bolt holes are in alignment.
Position any anchor brackets or mounting hardware for other components and then install the four mounting bolts and their washers. Tighten the mounting bolts to 10-12 ft. Ibs. (14-16 Nm) on 1986-93 engines or 12-18 ft. lbs. (16-24 Nm) on 1994-98 engines.
 
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bruceb58

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They change the gasket every few years it seems and the instructions regarding sealant change as well.

If the boat was run in salt water, I would suspect a possible intake manifold rust through issue but you said it doesn't.

If you want to go through the effort, pressure test the coolant section of the engine and see if it holds pressure. You will have to block off the hoses going to the manifolds and to the raw water pump.
 
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