Boat

Have Boat Questions? Ask a Boat Repair Expert.

Ask an Expert,
Get an Answer ASAP!

1997n merc 225 optimax. whats the fuel pressure on the high…

Customer Question
1997n merc 225 optimax...

1997n merc 225 optimax. whats the fuel pressure on the high side. don't think its dfi because there is no fuel rail with injectors by the heads

Mechanic's Assistant: Sometimes things that you think will be really complicated end up being easy to fix. The Marine Mechanic I'm going to connect you with knows all the tricks and shortcuts. Tell me a bit more about what's going on so the Marine Mechanic can help you best.

Wslow to rev past 1500rpm them slowly catches then goes. does not miss or sputter

Submitted: 9 months ago.Category: Boat
Show More
Show Less
Ask Your Own Boat Question
Answered in 1 minute by:
9/6/2017
Marine Mechanic: Tan, MerCruiser Certified Technician replied 9 months ago
Tan
Tan, MerCruiser Certified Technician
Category: Boat
Satisfied Customers: 11,282
Experience: 40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.
Verified

Hello, I'm Tan. Welcome to JustAnswer. I'm reviewing your question and will reply momentarily.

Ask Your Own Boat Question
Marine Mechanic: Tan, MerCruiser Certified Technician replied 9 months ago

Could I get engine serial number please?

Optimax is the DFI motor so if you don't have fuel rails at the cylinder heads this is not an Optimax.

Ask Your Own Boat Question
Customer reply replied 9 months ago
0g508022
Customer reply replied 9 months ago
i'm sorry u r correct its not a optimax
Marine Mechanic: Tan, MerCruiser Certified Technician replied 9 months ago

225 EFI fuel pressure is 34-36 psi.

We need to verify spark on all cylinders. This can be done with a spark gap tester or a timing light.

Ask Your Own Boat Question
Customer reply replied 9 months ago
if my fuel gauge is correct its around 45psi at idle
Customer reply replied 9 months ago
i have spark on all cylinders
Marine Mechanic: Tan, MerCruiser Certified Technician replied 9 months ago

That is way to much fuel pressure this will cause stumble and hesitation. The engine is flooding from to much fuel causing the issue.

To much fuel pressure is a failing fuel pressure regulator.

The regulator is # 20 in this pic. http://www.marineengine.com/parts/mercury_marine_parts/sn/0G508022/1225413TD/1086_100

Ask Your Own Boat Question
Customer reply replied 9 months ago
but the engine does not miss or stumble. revs up almost to get on plane then thats it for a minute then will slowly start to rev up then go. once on plane and going it runs fine.
Customer reply replied 9 months ago
evven when reved up to 1500 the engine is not missing or stumbling at that point.
Marine Mechanic: Tan, MerCruiser Certified Technician replied 9 months ago

You must verify the fuel pressure. Is that in gear? You cannot test how an engine performs out of gear.

Ask Your Own Boat Question
Customer reply replied 9 months ago
thats on the flusher not in gear
Marine Mechanic: Tan, MerCruiser Certified Technician replied 9 months ago

I would put the boat in the water and see how it performs. You cannot accurately troubleshoot this engine on a flush attachemnt. These engine require a certain amount of back pressure in the exhaust. If you don't have it the engine can run lean and cause hesitation. So we need to verify fuel pressure and that it is actually acting up. Let me double check that fuel pressure as I was going by memory recall.

Ask Your Own Boat Question
Customer reply replied 9 months ago
ok
Marine Mechanic: Tan, MerCruiser Certified Technician replied 9 months ago

That spec is correct. 34-36 psi.

Here is what the manual says.

Results: If pressure reading is 34 to 36 psi (234 to
248 kPa), the electric fuel pump is providing
fuel with enough pressure to be used by the
injectors. Pump malfunction is not the cause
of EFI trouble.
If fuel pressure is well below 34 psi (234 kPa), fuel delivery
to electric fuel pump, fuel pump failure or other
related problem exists. Follow low/high fuel pressure
flow charts.
If fuel pressure is above 36 psi (248 kPa) go to fuel
pressure regulator test.

Ask Your Own Boat Question
Customer reply replied 9 months ago
thanks let me test on water to verify
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a marine mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Tan Your Own Question
Tan
Tan
Tan, MerCruiser Certified Technician
Category: Boat
Satisfied Customers: 11,282
11,282 Satisfied Customers
Experience: 40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.

Tan 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

703 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

16,838 satisfied customers

Degree in Marine Technology. Gas and diesel marine mechanic.

Tan

Tan

MerCruiser Certified Technician

11,282 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
My I think 426 will not hold a map size any more. what shoul
my I think 426 will not hold a map size any more. what shoul I try to stop this … read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
I replaced the high pressure fuel pump and fuel filter on my
Jason, I replaced the high pressure fuel pump and fuel filter on my 2002 Suzuki DF140. Now i can get it to start. I didn't use a Suzuki fuel pump, I used a Quantum brand pump that their website says i… read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
16,838 satisfied customers
I just wanted to know if you know the wires on the back if
i just wanted to know if you know the wires on the back if trim gauge one harness has black. pink, orange, and light blue can you tell me what each wire go to I also have another set of wires one is b… read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
1997 150 EFI s/n 0G478636. Here's my problem. Engine will
1997 150 EFI s/n 0G478636. Here's my problem. Engine will quit intermittently but only while idling. Once it quits it will not restart. High pressure fuel pump will not come on with key in on position… read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
I'm not getting spark. I have a 3.0l lx mercruiser I have
I have a 3.0l lx mercruiser I have power to the coil at the purple wire. At the shift interrupt i have power at the purple side and Low bolts on the white and green wire side. … read more
Tan
Tan
MerCruiser Certified Technician
11,282 satisfied customers
The mounting base for my Humminbird 698 appears to be
The mounting base for my Humminbird 698 appears to be adjustable both horizontally and vertically but will not budge in either direction. How does this operation function? … read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
Trying to replace the factory stereo in a 2005 206 boat. New
Trying to replace the factory stereo in a 2005 Bryant 206 boat. New stereo has less wires than factory harness on the boat. Looking for wire schematic … read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
16,838 satisfied customers
Smartcraft indicates flashing and gas pump symbol. Replace
Smartcraft indicates flashing bell and gas pump symbol. Replace fuel filter and sensor. No changes resulted. Is this error code reducing motor performance … read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
I am getting an alarm on my mariner outboard moter. Battery
i am getting an alarm on my mariner outboard moter … read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
The starter won't engag. Battery are. New. Sounds like the
The starter won't engag JA: Sometimes things that you think will be really complicated end up being easy to fix. The Marine Mechanic I'm going to connect you with knows all the tricks and shortcuts. T… read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
I had vapor lock again this past weekend and left us
I had vapor lock again this past weekend and left us stranded on Fathers Day. Bad. I have put a blower to help cool the motor and used it according to the instructions before I turned it off and then … read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
16,838 satisfied customers
We purchased a V18 Targa combo a month ago. My wife noticed
We purchased a V18 Targa combo a month ago. My wife noticed a dent in the hull on both sides in the same spot. I did not notice these dents when we picked up the boat but nothing has been done since p… read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
16,838 satisfied customers
We can hear the cellanoid energize on the power tilt and
We can hear the cellanoid energize on the power tilt and power trim but it just won't move. We have had the boat out of the water for awhile. … read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
16,838 satisfied customers
We purchased a used 2014 Q7i Tahoe with MerCruiser &
Greetings. We purchased a used 2014 Q7i Tahoe with MerCruiser & AlphaOne Outdrive. We took out yesterday for the first time, and we didn't realize the previous owner had left the blue valve (for winte… read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
16,838 satisfied customers
We have a 2006 26 ft Grady, Yamaha 250 4 stroke. Was running
We have a 2006 26 ft Grady White, Yamaha 250 4 stroke. Was running great, nice and smooth, all of a sudden the RPMs dropped, and then we heard metal clacking noises … read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
I'm trying to take off a drive shaft housing from 50hp 4
hi i'm trying to take off a drive shaft housing from 50hp 4 strtoke merc, i took off all the outide bolts 13 0f em and still won.t come off i.m wondering if i have to take out the engine … read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
16,838 satisfied customers
Can i purchase an operator manual for my helix 9 from
can i purchase an operator manual for my helix 9 from humminbird … read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
16,838 satisfied customers
My Mercury EFI 150 outboard starts and idles fine, but the
My Mercury EFI 150 outboard starts and idles fine, but the RPM wont accelerate past idle. … read more
Clamp-onTech
Clamp-onTech
405 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