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496HO Engine performance issue.... opinions needed

HubbaHubbaLife

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Your symptoms sound like a water pressure sensor or water pressure issue. Then its going into guardian mode. I don’t see cleaning your injectors making any difference in the alarm or fixing the running issue.


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All opinions are always appreciated... In this case you may want to look back at some pictures I posted of peeled paint in fuel modulator. Looking like it got down stream into injectors as well. There's also several informed techs on this thread monitoring as this is a common issue with this engine series. I'll post as we move forward. Thanks.
 

HubbaHubbaLife

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Fellas.... I've been on phone with Mercruisers customer service guys and I gotta say I'm pleasantly surprised by their willingness to help. Its early still in their process but my instinct is if I had only used a Merc authorized dealer shop I'd have a free fuel system paying only the labor. For those still watching this thread Merc informs me that when marine fuel began adding ethanol it had an adverse effect over time on many sealants, rubbers and coatings built into engine parts. Over time issues have evolved.... and I'm sure there are many oem lawsuits as a result. So there we have it.
 

HubbaHubbaLife

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Update.... Merc customer service will be gifting new injectors. They sent me a list of Land N Sea authorized Merc dealers in my area. I found one and he'll be getting parts and doing install. He bills at 105/ hr. Next step is chasing Merc for that 1919.00 I paid out of pocket for Gen III Fuel Module part.... we'll see how they respond given the fact I didn't use their dealer. Quite the experience this has been.
 

HubbaHubbaLife

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Just spent a week down at my buddies in San Diego... he owns a charter boat cruise co.... and he has a 42' SeaRay with two new Merc Scorpions and one already went down in second week after install while other had a transmission fail .... so I'm not feeling too badly after seeing all that mess. He's got Merc on speed dial this week. His charter yacht biz is on fire last couple months due to covid pent up lockdown energy..... has around 4 vessels 42-65' and all booked solid. www.maitaicharters.com Yep, thats a plug fellas.

Fun biz model if enjoy topless servers/ bartenders
 

Lavey 29

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Man no offense to you but I would have had all this done in one to 2 weeks tops. I already done 23 of these since you started your post.
 

Lavey 29

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Since you posted the inflated cost of the new gen 3 cool fuel. The person whom sold you that if in fact it was a New gen 3 cool fuel module ONLY sold to you and no other parts for that $ 1919 ---- is a thief because full retail is 1279.36 for one brand new gen 3 cool fuel module Mercruiser as Merc is the only whom has these ( dealer only item ).
 

HubbaHubbaLife

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Since you posted the inflated cost of the new gen 3 cool fuel. The person whom sold you that if in fact it was a New gen 3 cool fuel module ONLY sold to you and no other parts for that $ 1919 ---- is a thief because full retail is 1279.36 for one brand new gen 3 cool fuel module Mercruiser as Merc is the only whom has these ( dealer only item ).
Hey my fellow Inmate... no offense taken whatsoever... I've only received excellent feedback on this forum. You'll notice from this threads detailed earlier comments that I assume boat costs will always be rape, lol.... I've been fortunate to have had a trusted tech on my boats for 20 years... so he relocated and I was left to the wolves of Newport Beach. Its great to learn that the fuel module should wholesale at ~$1300... I was scurrying due to covid tech/ part availability so perhaps paid premium.... and now I'm speaking with Merc directly on possible reimbursement. Doubt they'll help... I own that and hopefully won't get too worked up over it. I prefer not to get too overly involved or concerned on cars & boats tech stuff. But that said I will focus on an issue like this if I feel taken advantage of.... and thats why I'm thankful you've stayed engaged on this thread.... I'll pay my atty at 500/hr to come down on a retailer who takes a shot just for sport sake due to my address. I have very little patience for cowboy behavior at the shore if ya get my drift.
 

Lavey 29

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I understand what you are saying, Im looking at it alot of work and time lost with about zero time on the water for you this whole year. I feel bad for you in that way. Plus I understand its hard to find a boat shop that all works out for the end user to be 1000 percent happy with everything for boating and service work along with parts pricing. Anyways - The price I gave out of 1279. 36 was full retail to anyone whom steps in a merc dealership and buys it. I have never sold one higher than that actually a bit less to all my boat customers.

The reason I posted this out and about was because you posted Merc if possible could get 1919 payback to you for the purchase of that gen 3 cool fuel. I doubt it Merc will give you money back for a purchase on your own and especially an inflated price on top of retail. Sorry about that. Just saying and if you like I can delete my posts here if you find them not to anyones liking.

Will add thou my point also I know its hard to find a good service shop all over but there is some in every state to be had for great honest work. How to find that shop is thru word of mouth from boaters whom have used that serviced shop for many years. The bigger the fluff and dog and pony shows usually is the worst shops to have work done. Thats my imo.
 
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HubbaHubbaLife

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I understand what you are saying, Im looking at it alot of work and time lost with about zero time on the water for you this whole year. I feel bad for you in that way. Plus I understand its hard to find a boat shop that all works out for the end user to be 1000 percent happy with everything for boating and service work along with parts pricing. Anyways - The price I gave out of 1279. 36 was full retail to anyone whom steps in a merc dealership and buys it. I have never sold one higher than that actually a bit less to all my boat customers.

The reason I posted this out and about was because you posted Merc if possible could get 1919 payback to you for the purchase of that gen 3 cool fuel. I doubt it Merc will give you money back for a purchase on your own and especially an inflated price on top of retail. Sorry about that. Just saying and if you like I can delete my posts here if you find them not to anyones liking.

Will add thou my point also I know its hard to find a good service shop all over but there is some in every state to be had for great honest work. How tot find that shop is thru word of month from boaters whom have used that serviced shop for many years. The bigger the fluff and dog and pony shows usually is the worst shops to have work done. Thats my imo.
Appreciate your comments and don't take any of our comments down, I'm not sensitive about any of that. Believe me I called my few boating friends here in search of good references. Techs are apparently very specific now on what engines they want to work on. Most likely a supply/ demand thing at this time. The good news is I may have found a good tech for my boat through all this. I also regrettably identified a couple poor ones lol. Cheers.... and don't give another thought to how much summer boating I missed .... I prefer the fall/ winter & spring here at the ocean.... much softer water for speed boating fun. Presently waiting on injectors gifted from Merc...... Tick Tock
 

HubbaHubbaLife

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I understand what you are saying, Im looking at it alot of work and time lost with about zero time on the water for you this whole year. I feel bad for you in that way. Plus I understand its hard to find a boat shop that all works out for the end user to be 1000 percent happy with everything for boating and service work along with parts pricing. Anyways - The price I gave out of 1279. 36 was full retail to anyone whom steps in a merc dealership and buys it. I have never sold one higher than that actually a bit less to all my boat customers.

The reason I posted this out and about was because you posted Merc if possible could get 1919 payback to you for the purchase of that gen 3 cool fuel. I doubt it Merc will give you money back for a purchase on your own and especially an inflated price on top of retail. Sorry about that. Just saying and if you like I can delete my posts here if you find them not to anyones liking.

Will add thou my point also I know its hard to find a good service shop all over but there is some in every state to be had for great honest work. How tot find that shop is thru word of month from boaters whom have used that serviced shop for many years. The bigger the fluff and dog and pony shows usually is the worst shops to have work done. Thats my imo.
I just looked on price at the Merc dealer where that pump was bought; $1151.00.... now I'm a bit hot. I've just sent an email to the owner of Bayport Yachts who I've had communications with directly prior. Its obviously too late as I've paid invoice and was told I had to pay for parts prior to ordering. But I'd like to see his response as he's stated he wants my future service business and they also contract broker sales for 5% comm.
 

HubbaHubbaLife

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Thats correct... but he bought part through one.... and he just replied he's looking into those numbers I supplied him with. He let his service manager go in the middle of my work so could get interesting......
 

HubbaHubbaLife

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I understand what you are saying, Im looking at it alot of work and time lost with about zero time on the water for you this whole year. I feel bad for you in that way. Plus I understand its hard to find a boat shop that all works out for the end user to be 1000 percent happy with everything for boating and service work along with parts pricing. Anyways - The price I gave out of 1279. 36 was full retail to anyone whom steps in a merc dealership and buys it. I have never sold one higher than that actually a bit less to all my boat customers.

The reason I posted this out and about was because you posted Merc if possible could get 1919 payback to you for the purchase of that gen 3 cool fuel. I doubt it Merc will give you money back for a purchase on your own and especially an inflated price on top of retail. Sorry about that. Just saying and if you like I can delete my posts here if you find them not to anyones liking.

Will add thou my point also I know its hard to find a good service shop all over but there is some in every state to be had for great honest work. How to find that shop is thru word of mouth from boaters whom have used that serviced shop for many years. The bigger the fluff and dog and pony shows usually is the worst shops to have work done. Thats my imo.
Looky Looky...... guess I owe ya $300.... power of the RDP

Bill he did do our normal parts markup. But I have given you a discount and will credit you: $289.88 including sales tax. We will cut a refund check soon and mail to your CdM address.



Sea you on the Water,

J.R. Means III
President
Bayport Yachts Inc.
2530 West Coast Highway
Newport Beach, CA 92663
(949) 631-0228 Office
(949) 637-6671 Cell
 

Outdrive1

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All opinions are always appreciated... In this case you may want to look back at some pictures I posted of peeled paint in fuel modulator. Looking like it got down stream into injectors as well. There's also several informed techs on this thread monitoring as this is a common issue with this engine series. I'll post as we move forward. Thanks.

Please let us know if the fuel system fixes it. I still think you’re in guardian mode because of water pressure. Just my opinion though.


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HubbaHubbaLife

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Please let us know if the fuel system fixes it. I still think you’re in guardian mode because of water pressure. Just my opinion though.


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I'll be sure to let you/ everyone on this thread know the outcome. Just kinda taking these issues as they come.... when they found paint in fuel system all attention went directly at getting those parts replaced. Fascinating process... I'm not what I would call a super motivated boater so having it down all these months isn't too big a deal. Onward.....
 

HubbaHubbaLife

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Update..... located authorized Merc tech.... he's spoken with my Merc customer service contact... works like this, Merc tech orders fuel system parts from Merc in Wisconsin, then he sends invoice to Merc customer service contact and no money is paid on all these gifted parts. If I'd done this right earlier I'd have entire fuel system gifted based on the pictures of all that paint through pump & injectors. I pay labor. Next we'll see how long it takes to get parts delivered. I just signed an offer on the boat through a local broker to a buyer on Kona, HI.... contingent on successful sea trial via FaceTime ha. This'll be interesting!
 

HubbaHubbaLife

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Injectors & rail pulled.... cleaned Fri and re installed... Sat fingers crossed for a run.

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HubbaHubbaLife

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Tech just sent these... not really sure what I'm seeing.... we'll be taking boat out Monday am to do full diagnosis and see what we learn. He sounds like the right tech thus far.
 

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Shlbyntro

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Injectors look to be flowing dead nuts even which is great. The other pictures are pictures of the inside of the fuel rail where the injectors and fuel pressure regulator (or block off insert) go inside.

I'm seeing what looks like some small amounts of trash inside in the earlier pictures and than the after he cleaned them pictures.

All looks good to me!
 

HubbaHubbaLife

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Injectors look to be flowing dead nuts even which is great. The other pictures are pictures of the inside of the fuel rail where the injectors and fuel pressure regulator (or block off insert) go inside.

I'm seeing what looks like some small amounts of trash inside in the earlier pictures and than the after he cleaned them pictures.

All looks good to me!
Cool, thanks..... he got called out for emergency sinking client boat today so Tuesday we'll meet up and take boat out for run & diagnostics. If all goes well she'll be off to the Big Island of Hawaii to meet her new owner. He's asking for recommendations on local marine performance shop to do trim tabs, pro charger/ super charger & hydraulic steering upgrades... I'll start a new thread but OC / IE don't have any that I can think of.... we'll see what RDPers say.
 

HubbaHubbaLife

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Damn.... I got several performance boat shops off that thread..... dam, wish I'd have done that back in April when this mess all began.
 

HubbaHubbaLife

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Update..... cleaned rail & injectors replaced.... launched and out of the hole it was displaying same back firing popping and sluggish performance as we built speed and then all the sudden it came on full power. Ran it around hitting the 3-4500 rpm levels where it had struggled before and solid as new.

Next is mechanical survey paid for by Hawaii based next owner... if all checks out we're good.

Man what a process..... fingers still remaining crossed. I was gonna take one more final trip to Catalina after the survey but boat broker doesn't recommend risking it. Agreed after what I've been through these past 5 months.
 

Shlbyntro

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Update..... cleaned rail & injectors replaced.... launched and out of the hole it was displaying same back firing popping and sluggish performance as we built speed and then all the sudden it came on full power. Ran it around hitting the 3-4500 rpm levels where it had struggled before and solid as new.

Next is mechanical survey paid for by Hawaii based next owner... if all checks out we're good.

Man what a process..... fingers still remaining crossed. I was gonna take one more final trip to Catalina after the survey but boat broker doesn't recommend risking it. Agreed after what I've been through these past 5 months.

That popping and backfiring you experienced was likely just air bubbles working themselves out of the fuel rail. I wouldnt worry about it if it cleared up. I agree with your broker.
 

HubbaHubbaLife

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That popping and backfiring you experienced was likely just air bubbles working themselves out of the fuel rail. I wouldnt worry about it if it cleared up. I agree with your broker.
Brokers comment to me asking his opinion on a final post survey run, "Bill, its a boat, they break, do you want to risk it?" Nope.
 

HubbaHubbaLife

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For those still tuning in here's some compression data from way back in April when some were looking at spark plugs and wires a 496HO might fail ... I had them replaced and tech did a compression test... I just asked for and received results.... just sharing info for everyones knowledge... as stated I'm no tech

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SS-C

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For those still tuning in here's some compression data from way back in April when some were looking at spark plugs and wires a 496HO might fail ... I had them replaced and tech did a compression test... I just asked for and received results.... just sharing info for everyones knowledge... as stated I'm no tech

View attachment 931004

Ouch, those pressures seem quite low in my opinion.

If those readings are correct, I would say that engine needs a refresh.

If I’m not mistaken, a stock 496 HO would be in the 155-160 range.
 

HubbaHubbaLife

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Ouch, those pressures seem quite low in my opinion.

If those readings are correct, I would say that engine needs a refresh.

If I’m not mistaken, a stock 496 HO would be in the 155-160 range.
No kidding.... hmmmm.... strange that the tech commented positively. Lets see if any of our resident RDP master techs here respond.....
 

Shlbyntro

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For those still tuning in here's some compression data from way back in April when some were looking at spark plugs and wires a 496HO might fail ... I had them replaced and tech did a compression test... I just asked for and received results.... just sharing info for everyones knowledge... as stated I'm no tech

View attachment 931004

But they are all evenly low. It is unheard of for all cylinders to break down evenly. Obviously I wasn't there for the compression test, but I'd be more inclined to believe that these numbers are probably more reflective of a weak battery, dirty battery cable connections, weak starter, the actual compression gauge itself that was used, or any combination of such. Most likely in my experience: its a weak battery and/or compression gauge that reads a little lower than others.

It youre bothered by it, I'd have a compression test reperformed with a fresh battery and different compression tester before jumping to any expensive conclusions.
 

HubbaHubbaLife

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But they are all evenly low. It is unheard of for all cylinders to break down evenly. Obviously I wasn't there for the compression test, but I'd be more inclined to believe that these numbers are probably more reflective of a weak battery, dirty battery cable connections, weak starter, the actual compression gauge itself that was used, or any combination of such. Most likely in my experience: its a weak battery and/or compression gauge that reads a little lower than others.

It youre bothered by it, I'd have a compression test reperformed with a fresh battery and different compression tester before jumping to any expensive conclusions.
Thanks my man. Current tech is going out Tuesday for new test/ engine diagnostic survey
 

SS-C

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But they are all evenly low. It is unheard of for all cylinders to break down evenly.

I disagree; a well cared for engine can and will simply wear down evenly. In this case, with cylinder pressures relatively even, but low across the board, I would suspect piston rings.

Obviously I wasn't there for the compression test, but I'd be more inclined to believe that these numbers are probably more reflective of a weak battery, dirty battery cable connections, weak starter, the actual compression gauge itself that was used, or any combination of such. Most likely in my experience: its a weak battery and/or compression gauge that reads a little lower than others.

All this is true and can be contributed to low compression pressure readings. That said, this test was performed by a qualified mechanic and he should know this. The fact that the pressure readings are low should have rang his bell to make sure all the above was in good operating condition in order to perform an accurate test.

I’m sure the mechanic knows how to perform a competent compression test; my guess is that since the cylinder pressures were somewhat even he wasn’t so much concerned since the symptoms the boat was experiencing was not necessarily due to an aging engine.

If it were mine and was keeping the boat, I would not be happy with the results of that test. Those pressures are low for a stock 496. A wet compression test would help identify cylinder/piston ring condition. A competent leak down test would also be helpful.

But, if you’re selling anyway…
 

Shlbyntro

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I disagree; a well cared for engine can and will simply wear down evenly. In this case, with cylinder pressures relatively even, but low across the board, I would suspect piston rings.



All this is true and can be contributed to low compression pressure readings. That said, this test was performed by a qualified mechanic and he should know this. The fact that the pressure readings are low should have rang his bell to make sure all the above was in good operating condition in order to perform an accurate test.

I’m sure the mechanic knows how to perform a competent compression test; my guess is that since the cylinder pressures were somewhat even he wasn’t so much concerned since the symptoms the boat was experiencing was not necessarily due to an aging engine.

If it were mine and was keeping the boat, I would not be happy with the results of that test. Those pressures are low for a stock 496. A wet compression test would help identify cylinder/piston ring condition. A competent leak down test would also be helpful.

But, if you’re selling anyway…

Never in my time have I seen that. But maybe put a fresh battery in it and reperform with a new compression gauge to confirm 😉
 

HubbaHubbaLife

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Great insights you two. And SS-C welcome to my thread! I'll circle back after the Tuesday engine tests are in.
 

HubbaHubbaLife

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.... also wanted to give a special shout out to my homeboy Slbyntro for nailing the engine issue back in 4/6/20 after only reading my brief and non tech symptoms description. PHD stuff....

"That being said there is a service bulletin on your motor where paint likes to come loose from the inside of the fuel pump after the filters and gets sent down the line on the fuel system causing higher fuel pressure by clogging the fuel pressure regulator and sometimes causes erratic fuel injector behavior to where some injectors can be dumping fuel and others can not be giving enough fuel. All of which can cause the running issues you're describing"
 

HubbaHubbaLife

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Invoice to fix rail & injectors... sorry bout sideways angle... no rotation icon.

View attachment 931448
Ya know what just occurred to me.... if I'd found this guy a couple months ago he coulda just cleaned my fuel module rather than me paying $1700 for the part and can't recall the labor. Once my boat is officially sold I'll be totaling up what some paint peels cost me these last 6 months. Glutton for punishment.
 

HubbaHubbaLife

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Simply closing out this thread guys.... special shout out to Shlbyntro & Lavey29 for their expertise.... boats now on a cargo ship off to her knew owner on the big island of Kona, HI.... he's got 4 kids and seems to be a good dude. He'll be doing some engine upgrades, etc so its nice to know this little speed boat has a cool future continuing the salt experience in the big pacific chasing whales. Onward....
 
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