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300 verados choking out

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Old 03-10-2015 | 08:13 PM
  #11  
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Fuel pressure tests are the start to pinpoint problem areas and then move on as that is 100 % totally correct about The FSM they can be the problem child on top of fuel pumps and then possible attention to the fuel injectors. You know water that sits in the fuel injectors for any lengths of time really hurts them.

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Old 03-11-2015 | 02:57 AM
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The Merc SB = Service Bulletin posted up here is helpful and of course wants fuel pressure readings as part of the diagnostics . if only I was as smart about these new outboards compared to I/O's and inboards, I guess I could write my own ticket. Anyways thought back to what I know about the FSM = fuel supply module and the problems with them on the Verado's.

The jist is most likely in the FSM is running close to dry of fuel because the float switch is stuck and or has failed. A failed float switch will not turn on the low pressure fuel pump to refill the FSM or if the float is stuck in a position, the FSM will not have enough fuel to feed the high pressure fuel pump especially at higher rpms and or basically off idle. This will cause the high pressure fuel pump in the FSM to not properly flow the correct amount of fuel to the fuel injectors - hence a lean running condition and or starving the engine of fuel giving the reasons for the restricted rpms & cough you reported.

Merc is on their 4 or 5 th generation with the float switch to prevent it from failing due to the effects of E-10 fuels and water in the fuels that attack the float switch.

Next is to clean the FSM completely out spotless - buy and install the most current float switch and then replace with new, the reference hose for the regulator and install a new seal for the cover. All of this has to be done so do not skip any of it.

Then test to see how well this has fixed your problem. If not, then possible fuel pumps ( low & high) bad and then possible fuel injectors need to be flow tested and cleaned then flow tested again to see how well they are after the sonic cleaning.

Just an FYI - I flow, test and clean fuel injectors professionally. I have the machine to do so.

Do the simply repairs first - take fuel pressure readings, test engines on the water and fuel pressure readings on the water as well to see how all of this pans out.

This form of problems in the FSM will not show any codes no matter how many times you scan the engine. Good luck and hopefully I hit the nail on the head here.

Was the 3 other repair shops that looked at your engine, were they OEM Merc certified and trained on the Verado's. The Verado is nothing like any other of the Merc outboard lines. You have to find a shop that has a lot of indepth OEM training with them.
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Old 03-11-2015 | 07:12 AM
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Originally Posted by BUP

Was the 3 other repair shops that looked at your engine, were they OEM Merc certified and trained on the Verado's. The Verado is nothing like any other of the Merc outboard lines. You have to find a shop that has a lot of indepth OEM training with them.
+10

Sometimes you have to drive a long ways to find one. Bass Pro Shops, at least around here, has trained Verado Techs.
You might want to purchase a service manual with having 3 of them.

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Old 03-12-2015 | 10:37 PM
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Bass pro shop in Sarasota / Bradenton performed the work last full scan etc cost me $400
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Old 03-12-2015 | 10:55 PM
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Possible what I posted will get you fixed up hopefully. Bass Pro Shops charged you 400 bucks for scanning all 3 engines not one engine is this correct ???

No offense but Bass Pro and Cabela's cherry pick what to work on. Some will only touch what they sold and some will only work on boats 5 years old.. Not saying all of their stores but some of their techs keep it that way.
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Old 03-12-2015 | 10:59 PM
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Hey I thought you were in CT not on the westcoast Florida ? I know who could fix you up with your Verado's but I will have to checkin with them and you. It might not be cheap either but that's the they way it is for the saltwater ocean front certified marine repair shops plus who are very current with their OEM's training..
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Old 03-13-2015 | 02:51 AM
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From http://www.veradoclub.com/index.php?topic=23.0 site titled great verado dealers. Many more are on there.

Location: Fort Lauderdale area
Posts: 9963



Great Verado Dealers

« on: March 06, 2008, 05:11:34 am »



There are two that come to mind here in South Flotrida - both certified with great facilities on the water in and around Fort Lauderdale

Lauderdale Marina - Ask for Matt the service manager

Sundance Marine in Fort Lauderdale - Ask for Randy - also the service manager

Hideaway marine - Pompano - Ask for Joe

Nothing fixed that does not need it, and both will let you do some of the work yourself before hand... Cool Cool.



Re: Great Verado Dealers

« Reply #12 on: July 12, 2008, 09:30:27 am »



And certainly FCM's home - First Choice Marine in the Tamp St Pete area!

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Old 03-13-2015 | 12:45 PM
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If you are going over to Ft. Lauderdale or in that area let me know. I know a Master tech and he is very good on Verado's. I will see if he will work on it after hours. If you are staying put on the westcoast of Florida I have 2 and one comes highly recommended because they specialize in Verado's.

I would try first what I posted because the FSM and the float switch are a very common problem. It still would be wise to check fuel pressures and running conditions as possible the fuel pump(s) might be bad along with a fuel injection service. Start at the FSM first then see if anything is next. I have never been on or even looked at the Verado club website to know what is good info or not.
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Old 09-26-2018 | 06:05 PM
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Originally Posted by notriteJohn
I have triples and the center motor is breaking my balls
Scanned all 3 motors no fault codes and reset smart craft and re-sicronised
Changed spin on fuel filter
It has good 91 octane gas
The motor starts and idles fine but won't rev over 2,000 rpm under load (it chokes out) and I can't figure out why it's been to 3 different mechanics so far
Could it be throttle position sensor?
Drive by wire communication issue?
Feul delivery problem?
Hi, i know this is an old post. But was wondering what was the rix. I have a pair of mercury verados 300's. But only one is doind the same thing.
please let me know. Thanks
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Old 09-26-2018 | 07:41 PM
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Pull the cowling off and check the wires going through the rubber grommet in to the lift pump. Had one that the coating on the wire cracked and caused the wire to corrode and eventually lose contact just enough it would cause the same symptoms you are describing. Might not be your problem but it’s worth taking a look.
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