Boat

Have Boat Questions? Ask a Boat Repair Expert.

Ask an Expert,
Get an Answer ASAP!

Boat
This answer was rated:

1988 Mercruiser 4.4 alpha one I changed out the throttle and

shift cables to mu control...
1988 Mercruiser 4.4 alpha one I changed out the throttle and shift cables to mu control box... we took the boat out ran perfectly for about an hour opened it up to about 35 mph was running real good all of a sudden we let off the throttle went to throttle up again and once it hit 3000-3500 rpm the engine would bog down and have no acceleration and stall.... we started it back up will run perfevtlctky at lower rpms but give it more throttle and it dies the same and stall?
Show More
Show Less
Ask Your Own Boat Question
Customer reply replied 2 months ago
4.3 sorry
Answered in 1 hour by:
9/22/2017
Jason
Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 16,346
Experience: Degree in Marine Technology. Gas and diesel marine mechanic.
Verified

Good morning, my name is ***** ***** am I speaking with? I read what you wrote. Mercury engines are cataloged by serial number, do you happen to have that number handy so I can see exactly which version of the 4.3 you have? Next, is there a history to this engine, have you ever seen it run correctly?

Ask Your Own Boat Question

I can't make out the serial number in that picture. Are you able to make out what the numbers are?

Ask Your Own Boat Question
Customer reply replied 2 months ago
No I'm sorry it's very blurry it's very hard to see the exact numbers

Is the engine carbureted or fuel injected?

Ask Your Own Boat Question
Customer reply replied 2 months ago
Carbureted

Got it. Have you done anything on your own yet to troubleshoot the issue? Did you have questions that you specifically wanted me to answer, or would you prefer if I explained how we would approach this type of symptom in the shop?

Ask Your Own Boat Question
Customer reply replied 2 months ago
This just happened last night I have it in a boat slip... I mean the first thing that came to my mind was plugs wires cap and rotor...

Is the engine actually stalling or is it just dropping power?

Ask Your Own Boat Question
Customer reply replied 2 months ago
It would start to bog down at 3000-3500 rpm loose power then stall

Got it. Give me 10 minutes to get something typed up for you.

Ask Your Own Boat Question
Customer reply replied 2 months ago
Ok great thanks
Customer reply replied 2 months ago
I'm at work now so I'm not at that boat till later

There definitely may be more than 1 thing wrong with the engine. But stalling typically means the engine is running out of fuel. And fuel is not getting from the tank to the inside of the engine. When the cap, rotor, plugs or plug wires go bad what will happen is those effected cylinders will either misfire or not fire. If the engine was running on say just 4 cylinders instead of all 6 because of a bad ignition component, it would still stay running as long as those firing cylinders were getting fuel. The engine might very well benefit from a tune up. But that by itself is not likely causing the stalling, The stalling is most likely because is the engine is simply running out of fuel. Here is what we would do in the shop.

1. Change all the fuel filters. If the filters are clogged then obviously fuel is not going to make it's way from the tank to the carb. Some models have filters inside the fuel pump as well as one in the carburetors fuel inlet.

2. As simple as this sounds you always start by running it off of a different fuel tank, like a small plastic portable tank. Half the time there isn't anything wrong the motor itself, but rather something wrong with the boats fuel system. This can be a pinched or collapsing fuel line, bad or old gas, or a bad anti siphon valve. Marine engines are very sensitive as to the quality of the fuel, and if any part of it is over 90 days, the fuel itself is always going to be suspect. This is a pass or fail test, and the engine is either going to run better or it is not. If it does run better, on this portable tank, first change the anti siphon valve and retest with the engine hooked back up to the boats fuel tank. If it goes back to running poor on the boats fuel tank, that tank will need to be pumped out. Bad anti siphon valves are a common problem, when they go back they create a blockage and restrict the amount of fuel that flows to the engine. If the engine does not get enough fuel it obviously will not make full power. Click this link, this explains more on the anti siphon valve and why they go bad. http://www.sterndrives.com/anti-syphon-valve.html. On this anti siphon valve there is an inlet side and an outlet side. The inlet side faces the fuel tank, the outlet side faces the fuel line. When the engine runs, the fuel pump creates suction. This suction pulls the check ball off of it's seat and fuel is allowed to flow around it. The problem with this is over time the spring in the valve will get weak or simply break. When that happens the check ball will be free to jump to the outlet side of the valve and create a blockage/restriction on the outlet side of the valve. If the spring is simply weak and not broken, this will more or less happen at random. Click this link for a picture, it will make more sense once you see it Http://imgur.com/a/tpq4H. The anti siphon valve itself is located at the fuel tank, where the fuel line connects. If you pull the fuel line off the tank you will see a hose barb, that hose barb is the anti siphon valve.

3. Check the fuel pressure. Fuel pressure needs to be at least 3 psi at all speeds. This needs to be checked with the boat in the water and the boat going at full speed. If fuel pressure is below 3 psi then the fuel pump is weak. You want to make sure you test this after #2. If there is a bad fuel line or bad anti siphon valve will cause fuel starvation and low fuel pressure.

4. Finally. If all the filters are changed, and if there was no change when running it on the portable tank, and if the fuel pressure was good, then the problem is going to be inside the carb itself. The carb's internal fuel jets are going to be semi-clogged and not allowing fuel to make it's way from the carb and into the cylinders. Does that all make sense. That is where you stand on your end and what the problem is. I think that should do it but I work for tips so I do want to make sure you are happy with my service before you go. If you had a further question on the issue by all means feel free to ask. If not, Just in case you do not understand the way the website works (and some folks do not). You do have to put forth a positive rating in order for it to credit me for helping you. When ratings are not done, the website simply keeps your deposit and they will not credit me. The ratings box is located at the top of the screen. To rate, you must select the star you wish and also confirm it. Please let me know if you run into any problems or errors when trying to do it. If you do have a problem, or if you can not see the ratings box which is at the top of the screen. Please reply back "I rate Jason's service _______" and fill in the blank.

Please note that our question sessions never close out, so if you need to come back later down the road with follow up questions to the issue, you can do so at any time, even after putting through a rating.

Thanks in advance, and good luck
Jason

Ask Your Own Boat Question

It took me a while to write all that for you. It looks like you read my answer and left without selecting a rating for my service, replying back, or simply thanking me. Was there something else?

Jason
Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 16,346
Experience: Degree in Marine Technology. Gas and diesel marine mechanic.
Verified
Jason and 87 other Boat Specialists are ready to help you
Ask your own question now
Customer reply replied 2 months ago
No sorry I read it quickly cause my boss called me I was gonna read it more clearly when I take break but I will rate it now
Customer reply replied 2 months ago
I changed out the fuel filters and the anti siphon valve took the boat out today same thing happened so I looked into the carberator and the valve that's on top of the carberator that allows air into the carb is not moving it was wide open allowing full air to enter the carb... i wire tied the arms on the side of the carb got my boat back to the slip as it was functioning normally with me wire Tyeing it... I have pictures of my carb am I missing a spring or something why that air valve on top is not moving with the throttle cable I can move the arms with my fingers and can move it no problem but seems like something may be missing why it is not moving with them throttle control..
Customer reply replied 2 months ago
I assume this is the choke but it's fully open does not move with throttle and stalls out the motor at higher rpms when I wire tied it so it would move the boat ran fine
Customer reply replied 2 months ago
The number listed on the carb is 9600s 2195

Good morning. Are you able to send a picture over of what you are looking at?

Ask Your Own Boat Question
Customer reply replied 2 months ago
I sent over four pictures

Okay I see it. That plate is the choke plate, and it's supposed to be open when the engine is above 75F degrees.

Ask Your Own Boat Question
Customer reply replied 2 months ago
but in the side of the carb where the throttle cable is those arms that control the choke plate do not move with the throttle control like something is missing like a spring

I​s this choke plate closing on it's own when the engine is running?

Ask Your Own Boat Question
Customer reply replied 2 months ago
No it does not move kind stays in the upright position

If it's not closing on it's own then it's not going to contribute to the problem. That would only be a problem if it actually was closing on its own.

Ask Your Own Boat Question
Customer reply replied 2 months ago
Ok no prob I had read that the plate should be almost closed about an 1/8"-1/4 open in full throttle

The plate should be just very lightly closed when the engine temps are roughly 75F or lower, and more or less fully open when the engine is warmed up. As long as that plate isn't closed, it wouldn't be causing the problem.

Ask Your Own Boat Question
Customer reply replied 2 months ago
Hey so I changed anti siphon valve, fuel pump, water fuel separator filter I even bought a new 4 barrel carb and changed that...I took it out today and I got to the entrance to the bay after say 2500 rpms for 1 minute and it started bogging down and stalled... I turned around and started heading back to my slip got half way through the lagoons and it stalled out at wake speed.. started it again same thing kept happening... a boat passsed us and towed us back to out slip...

Did you go through the entire list of things that I wrote to check? Did you run the engine off of a different fuel tank? Did you change all the fuel filters? Did you checked the fuel pressure?

Ask Your Own Boat Question
Ask Jason Your Own Question
Jason
Jason
Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 16,346
16,346 Satisfied Customers
Experience: Degree in Marine Technology. Gas and diesel marine mechanic.

Jason is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

Meet the Experts:

Dominick

Dominick

Marine Mechanic

1,009 satisfied customers

25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified

Ted G.

Ted G.

Rigger, Diagnostician

695 satisfied customers

40 years boating, Safe boating instruct., Offshore Race promoter, Failure Analysis, Expert Witness

John White

John White

Marine Mechanic

306 satisfied customers

11 years experience working on outboards, inboards, sterndrives & pwcs

Jason

Jason

Marine Mechanic

16,346 satisfied customers

Degree in Marine Technology. Gas and diesel marine mechanic.

Tan

Tan

MerCruiser Certified Technician

11,001 satisfied customers

40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.

Jeff G.

Jeff G.

Marine Mechanic

4,728 satisfied customers

42 years experience, Certified Master Technician, All Major Outboards, Sterndrives, Hi-Performance

Captain Dave

Captain Dave

Marine Mechanic

2,672 satisfied customers

USCG Licensed Captain, 20+ Years Boating, Fishing, Maintenance and Repair Experience

< Previous | Next >

Related Boat Questions
37 maxum 2001. Going through fuel filters too fast, Boat
37 maxum 2001. Going through fuel filters too fast … read more
Tan
Tan
MerCruiser Certified Technician
Certified Marine Technician
11,001 satisfied customers
I have a1997.5 sea doo GSX limited. The engine is a 951/947
I have a1997.5 sea doo GSX limited. The engine is a 951/947 which is white in color. I made the mistake of towing the machine without pinching off the water line which caused water to get inside the e… read more
Boat Doc
Boat Doc
122 satisfied customers
Im getting no spark from spark plugs. Motor ran perfect when
motor ran perfect when i pulled it out of the water, 3 weeks later when i put it in the water it wouldnt start, took spark plug out to see it it would spark and it doesnt … read more
Jason
Jason
Marine Mechanic
16,346 satisfied customers
I have a volvo Penta 130 with twin solex 44pai carbs. I have
I have a volvo Penta 130 with twin solex 44pai carbs. I have just stripped and cleaned them our, and fitted new kits into them. what float level do I set? can't seem to find the setting anywhere. Than… read more
Jason
Jason
Marine Mechanic
16,346 satisfied customers
Intermittent alarm. no trend. temp good, oil pressure good,
intermittent alarm. no trend. temp good, oil pressure good, lanyard good. running along and it just beeps and engine jerks then picks right back up and runs. feels like electrical miss. … read more
Jason
Jason
Marine Mechanic
16,346 satisfied customers
Recently purchased a 2005 Silverton 34' Convertible with
Recently purchased a 2005 Silverton 34' Convertible with twin 6.0l gas Crusaders with twin engine controls (single helm station on the upper fly-bridge). That being said,, I hate the dual set of engin… read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
I have a 2002 mercruiser 454 mpi. the fuelpump dose not come
hello, I have a 2002 mercruiser 454 mpi. the fuelpump dose not come on when I turn the key on. tested the pump by jumping it at the relay and it is good. tested the relay by putting on the other motor… read more
Jason
Jason
Marine Mechanic
16,346 satisfied customers
I need a gas cap for a Merc 4hp two cycle. I need a gas cap
I need a gas cap for a Merc4 two-cycle. Where can I get one? … read more
Jason
Jason
Marine Mechanic
16,346 satisfied customers
Have an 898C system and can't get the new Navionics Platinum
have an 898C system and can't get the new Navionics Platinum card to stay down in the SD card slot. I can hold the card down and the card works but soon as I release it the depth line go away. Any sug… read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
I have a 2003 Sea Ray 320 I just had an engine replaced the
I have a 2003 Sea Ray 320 I just had an engine replaced the problem now is none of the instruments work I can't get that engine hatch to go up or down none of the 12-volt instruments on the panel work… read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
No water coming through the bottom but through the top, 240
No water coming through the bottom but through the top … read more
Jason
Jason
Marine Mechanic
16,346 satisfied customers
It is a boat and not running correct. Testing injectors (2 )
it is a boat and not running correct. Testing injectors (2 ) they are suppose to read 230 barr and actual reading 260 barr. … read more
Jason
Jason
Marine Mechanic
16,346 satisfied customers
1970? Mercruiser 165 in a 1970 Tri Hull Thunderbird boat
1970? Mercruiser 165 in a 1970 Tri Hull Thunderbird boat won't stay running. See video here https://www.youtube.com/watch?v=MBYia1Gdn9cI'm trying to get this running, and need to know why it is cuttin… read more
Jason
Jason
Marine Mechanic
16,346 satisfied customers
Want to swap 12o hp omc engine with 140hp omc engine. Will
Want to swap 12o hp omc engine with 140hp omc engine. Will they interchange … read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
I have a year old dragonfly 5 unit installed. It turns on
I have a year old dragonfly 5 unit installed. It turns on with the main 12v boat switch to show the dragonfly name, but will not accept any input from the panel buttons, including the power off button… read more
Boat Doc
Boat Doc
122 satisfied customers
Looking for suitable outboard for one off design 6.5m
Looking for suitable outboard for one off design 6.5m aluminium catamaran weight around 2200 kg. calculated power needed for my usage around 210hp. Evinrudes seem to have two versions of E-Tec G2 66 d… read more
Jason
Jason
Marine Mechanic
16,346 satisfied customers
It is a 2006 rxtsupercharged sea doo it beeps all the time
it is a 2006 rxtsupercharged sea doo it beeps all the time until we unplug the battery … read more
Boat Doc
Boat Doc
122 satisfied customers
Which lowrance hook 4 series has all the bells and whistles?
Which lowrance hook 4 series has all the bells and whistles? I don't want to buy one and then realize I should have got a better 4 series and I just didn't research enough, I plan on using it on a lar… read more
Boat Doc
Boat Doc
122 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x