Marina installed new Manifolds/ Risers..now engine is only running on 5 cylinders

[BajabossJD]

Hello everyone.. Long time no talk!


I have done the awful..tough job of changing out manifolds, risers in the past on my 95 7.4 RWC engine.. This time, I decided to have the big boat yard at my marina do the job.

I had OEM manfiolds and risers with 5 hours on them installed by the marina. The boat was running great when I dropped it off to them. After some serious delay, they completed it and I tried to fire it up. It ran AWFUL! Missing on more than one cylinder for sure. They had their mechanic come take a quick look and he was able to pull off 3 leads while the engine was running and their was ZERO difference in the way it ran. It was 2 cylinders on one side and 1 cylinder on the other side.

What could they have messed up with installing these? We checked the plugs to make sure they weren't cracked and we also made sure the wires were on correct.


Now they say the starter is shot and they are ordering a new one (which it turned over fine to show the young mechanic the rough running).

I stopped by when no one was looking and saw the plugs out and quarts of oil opened by the back of the boat..WTH? Perfectly running and now it wont even start (and when it does..huge miss) Could bad gasket placing cause this issue instantly? I did see a weep of water coming out of the port manifold/riser gasket when I looked. The boat has been started once since they "completed" this work. This is a place that deals with 50' + MY...very respected. Thoughts?

Thanks,

Joe
454 Carb/ B1

 

[alldodge]

Hello everyone.. Long time no talk!


I have done the awful..tough job of changing out manifolds, risers in the past on my 95 7.4 RWC engine.. This time, I decided to have the big boat yard at my marina do the job.

I had OEM manfiolds and risers with 5 hours on them installed by the marina. The boat was running great when I dropped it off to them. After some serious delay, they completed it and I tried to fire it up. It ran AWFUL! Missing on more than one cylinder for sure. They had their mechanic come take a quick look and he was able to pull off 3 leads while the engine was running and their was ZERO difference in the way it ran. It was 2 cylinders on one side and 1 cylinder on the other side.

What could they have messed up with installing these? We checked the plugs to make sure they weren't cracked and we also made sure the wires were on correct.


Now they say the starter is shot and they are ordering a new one (which it turned over fine to show the young mechanic the rough running).

I stopped by when no one was looking and saw the plugs out and quarts of oil opened by the back of the boat..WTH? Perfectly running and now it wont even start (and when it does..huge miss) Could bad gasket placing cause this issue instantly? I did see a weep of water coming out of the port manifold/riser gasket when I looked. The boat has been started once since they "completed" this work. This is a place that deals with 50' + MY...very respected. Thoughts?

Thanks,

Joe
454 Carb/ B1

My guess is they pulled the plug wires off to get them out of the way and don't know how to put them back in the correct order. 1-8-4-3-6-5-7-2
Exhaust manifolds will have no issue with the firing order. I would suggest get the boat back from them as soon as possible and cut your looses, they do not know what they are doing

 

[BajabossJD]

Thanks for the input. I'm going there first thing in the morning. It's the large set of numbers on the rotor correct? (plug wire numbers.. There's a small set and larger set of numbers). Hopefully it's just the firing order out of whack.

Joe

 

[NHGuy]

Yes, but then get a new set of Mercruiser OE riser-manifold gaskets. I'd do this because of the water weeping. You can't allow any water into the exhaust stream, that causes major troubles.
Sure, first check if the wires are wrong.
But then, whether it runs well or not, do the gaskets, they only cost $10 or $15. Clean off the mounting surfaces with a scraper or a couple of razor blades. If you have a surface prep "whizzer" like mechanics use they are best. But you can get them clean by hand too. Make sure the surfaces are flat. If they are rotted or bumpy flat file them. The risers are then torqued to 25 foot lbs.
Reused or worn gaskets will leak.

 

[Alumarine]

Yes, but then get a new set of Mercruiser OE riser-manifold gaskets. I'd do this because of the water weeping. You can't allow any water into the exhaust stream, that causes major troubles.

What are the consequences of water weeping into the exhaust stream? Are the OE gaskets better than aftermarket?

 

[Bt Doctur]

more like the water leaking into the exaust port of a cylinder, the mercruiser graphite type gaskets are much better with a light coat of Perm-atex Aviation sealant

 

[Alumarine]

more like the water leaking into the exaust port of a cylinder, the mercruiser graphite type gaskets are much better with a light coat of Perm-atex Aviation sealant

Ok, I see. I was thinking the water would go the other way out the exhaust. It makes sense now.

 

[BajabossJD]

Marina called before I could get there this morning. Compression checked and 0 PSI in cylinder 1 and 80 psi in cylinder 3.

2 months ago with the old risers I had compression checked and all were good, except cyl 3 was 80psi. Engine ran fine and I was gonna run it for the summer that way.

New manifolds on and now 0 psi in cylinder 1. I am thinking its a valve issue and I am sure the head has to come off. Question is..why did it run great and then now after the work...head overhaul needed!?


Thanks,
Joe

 

[BajabossJD]

Just to confirm..There is a almost zero chance of a manifold/ riser installation causing a dead #1 cylinder? Oil has been perfect and as stated everything was running well until I handed it over. I may have to get lawyers involved as the marina isn't telling me exactly what they did.

Thanks,
Joe

 

[BajabossJD]

*UPDATE*

They fired the mechanic that worked on my risers. They are arn't saying it's their fault, but they arn't saying its not my fault. They took off the valve cover and saw a broken push rod on #1. They said there was no water in the engine anywhere. They are confident that once the new push rod comes in on Tuesday, it should fix the 0 compression issue. Other cylinders are #175psi (#3 was a little low..85PSI). I think they said that push rod was slightly bent..(had a spark plug burn off in that cylinder once).

Thoughts? Seems odd that this just happend with such low hours on my rebuild (my crappy rebuilder probably resused the old push rods).

The marina doesn't think any of the valves are bent.

Thanks,
Joe

 

[BajabossJD]

BTW.. I have the entire interior out of the boat (including the engine hatch). I had a tarp covering the engine and they took about a week + to complete the riser install. The service guy kept complaining about my tarp and how it kept flying off. He made a note today to tell me that they are gonna keep it down with bricks while we wait for the push rod. Rain + Guy got fired = Water in my cylinder to break rod? Boat was never ran more than idle and hasnt been under load since I left it with them.

Joe

 

[NHGuy]

It sounds as if they are taking responsibility for the situation. Let them do the repair. Take good notes and tell us how it turns out. Just cause they aren't admitting it isn't stopping them fixing it. If it ends up not to your satisfaction THEN start complaining.
And don't sign off on any waivers. If they are in the wrong it might give them an out.

 

[NHGuy]

Yes rain could get down the carb. But whatever, they know that and would cover it. If not covered it's their fault, they are the experts.