Boat

Have Boat Questions? Ask a Boat Repair Expert.

Ask an Expert,
Get an Answer ASAP!

Boat

Mercury 402 won't start after welding. Motor ran doggedly

Customer Question
Mercury 402 won't start after...
Mercury 402 won't start after welding.
Motor ran doggedly before repairs as carb float was 1/2 full of gas - now will not fire, even on Ether. Forgot to pull harness before welding.
Ohmic values are ok per SELOC manual and other sites - values as follows:
Stator - 5.9k across red and blue
Stator - 51.2 red to ground
Trigger - 850K between leads
Ignition Coils - .4 Ohms primary/ 1K secondary
DVA readings :
Stator - w/ rectifier disconnected 38V / 308 V
Stator - w/ rectifier connected 31V/ 296 V
Trigger - 1.5V across terminals / .7V to ground each terminal
Ign Coils - input 220V and 207V coil 1 and 2
Ign Coils - output 20V and 17V with DVA, else meter reads .5v each on DC scale without DVA.
Plugs spark outside of engine- after welding plug one had 1 ohm short due to aluminum build up between electrode and ground - this was removed and plug reads open now.
Switch box was replaced since kill lead read 1 Ohm short to cylinder one - with new switch box it read .7 Megaohms. No voltage detected on kill lead from key switch
Appreciate any insight.
Submitted: 2 years ago.Category: Boat
Show More
Show Less
Ask Your Own Boat Question
Answered in 4 hours by:
8/31/2015
Marine Mechanic: Joe, Marine Mechanic replied 2 years ago
Joe
Joe, Marine Mechanic
Category: Boat
Satisfied Customers: 7,252
Experience: ASE, electronics, Marine mechanical and electronics, pwc, wiring, all around repair tech,
Verified

Hello,

Thank you for allowing me to assist you, my name is ***** ***** I will be happy to assist you with your concern today.

I am just seeing if you still need assistance with this problem? The reason I ask is because I see that your question has not been answered sooner and I wanted to make sure if you still needed help.

In some cases a question may sit due to several different things including the amount of the deposit/question value, time it was asked, the complexity of the question, number of experts that can help you at a certain time, lack of detailed info and so on. My objective that I wish is to make sure that if you still need help that I can at the very least reach out to you and attempt to help you. I may not have exactly the experience to deal with a certain problem but instead of you not receiving any answer at all I would at least like to reach out and attempt to help you.

At this time please feel free when you are ready to reply back to me and ask to continue working with me, another expert or if you no longer need help please just let me know exactly what you wish to do.

Thanks,

Joe

Ask Your Own Boat Question
Customer reply replied 2 years ago
No one has answered my question yet
Marine Mechanic: Joe, Marine Mechanic replied 2 years ago

Good morning,

You should not be reading 17 or 20 v on the coils, the pos + side of the coil should read 12v dc and the neg should pulse with a test light during cranking. There is an extremely high chance it took out the switch/cdi box, which you found and replaced it looks like.

Your going to have to go through all of your electronics, what took place can damage more than one thing, in fact it can overload an entire system and fry so many things that it is hard to find them all.

What happens is the stray current makes it's way through the circuits since they are left as completed circuits, too many amps and it starts frying things, you will also need to visually inspect all wires as there's a chance it also melted wires.

Thank you!

- Joe

Please rate my answer when ready. Bonuses are appreciated.

If for any reason you are not satisfied please reply back to me for further assistance to which I will be glad to help you. If you have any problems for any reason please reply back and let me know.

Thanks again for using justanswer and have a great day!

If you need any further assistance you can reply back at any time for my help.

I'd be happy to answer any other questions you have even if not related.

/* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;}

Ask Your Own Boat Question
Customer reply replied 2 years ago
I realized my output reading on the coils were done incorrectly - with no 'load' - i.e. I was reading off the plug wire with no plug attached- plugs do spark outside of motor while cranking. Engine won't fire on Ether. Readings are from new Switch box.I don't have 12v going into coils; I have (DVA reading) 220v and 207 respectively on green input leads from Switchbox at positve terminal of coil. Is this incorrect?
Marine Mechanic: Joe, Marine Mechanic replied 2 years ago

Is that with your voltmeter set to dc voltage? there should be no way you are seeing 220v, these are 12v systems. The stator will produce ac voltage and the regulator converts into dc and regulates it but nothing near 220v be that ac or dc 220v is way too high and honestly so much so it almost seems to suggest the meter setting.

In your question you stated "will not fire" and thus my understanding no spark as that is what no fire refers to, thank you for the clarification on that. You have spark but, using an in-line spark tester or gap tester, how good is the spark? And does it miss?

You in a nut shell need correct spark and timing, compression, air and fuel to get it to start.... we need to find what is missing.

Thanks,

Joe

Ask Your Own Boat Question
Customer reply replied 2 years ago
Meter was set to DC Voltage - auto range to 1000V. Reading was taken using DVA adapter. Conversely the Stator readings were 31V and 296V using DVA adapter set to same scale as above. Per troubleshooting guide on the Switchbox ,the Stator outputs are correct (30V + on low voltage lead and 180V+ on High Voltage Lead). To wit, this High Voltage from the Stator seems to be where I'm getting the high voltage input to the ignition coils- Thunderbolt Ignition.I'll get an in-line spark plug tester and report back.
Marine Mechanic: Joe, Marine Mechanic replied 2 years ago

Now I understand what you were explaining, sorry I missed that, somehow I didn't realize you were using an adapter.

Since you have spark I am not worried about testing the voltages at this time on the coil such as pulse - , because you do have spark.

Since you are needing to check strength, color and overall spark, this is the type of tester I am referring to: http://www.ebay.com/itm/CDI-Spark-Tester-511-9766-/231660232149?_trksid=p2141725.m3641.l6368

Thanks,

Joe

Ask Your Own Boat Question
Customer reply replied 2 years ago
Used an single -adjustable spark-gap tester - I tested to 30KV at approx 3/4 of an inch gap. Sparks were blue in color and regular in interval.
Marine Mechanic: Joe, Marine Mechanic replied 2 years ago

Good morning,

That seems to indicate good spark then.

Question, when you spray starting fluid into the carb throat does the engine have any signs of life or change?

Thanks,

Joe

Ask Your Own Boat Question
Customer reply replied 2 years ago
No but I may not be using enough - I used a quick spray at the screen cover. I did get the motor to back-fire twice last night with no Ether, extended cranking and using the choke. I have set the Idle screw to 1 full turn open from fully seated. I was going to try and get some fresh fuel tonight just to be sure I wasn't overlooking the obvious.
Customer reply replied 2 years ago
Tried fresh fuel and no change, other that the backfire occasionally - I even pulled one plug at a time to see if I could isolate the bafire to one or both cylinders. I was able to get both to backfire with the opposite plug pulled. As a last resort I performed a compression test and both cylinder registered 130 psi. I located the TDC mark on the flywheel and will try tweaking the trigger alignment tonight
Marine Mechanic: Joe, Marine Mechanic replied 2 years ago

Did you try more starting fluid again?

Thanks,

Joe

Ask Your Own Boat Question
Ask Joe Your Own Question
Joe
Joe
Joe, Marine Mechanic
Category: Boat
Satisfied Customers: 7,252
7,252 Satisfied Customers
Experience: ASE, electronics, Marine mechanical and electronics, pwc, wiring, all around repair tech,

Joe 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

691 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

15,567 satisfied customers

Degree in Marine Technology. Gas and diesel marine mechanic.

Tan

Tan

MerCruiser Certified Technician

10,957 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
It's a 1988 8HP Honda outboard and the throttle won't turn
It's a 1988 8HP Honda outboard and the throttle won't turn either way. … read more
Boat Doc
Boat Doc
107 satisfied customers
94 venom 200 I lost all fire so I changed power pack now
94 johnson venom 200 I lost all fire so I changed power pack now motor runs but does not plan out motor runs real bad if i unplug white and black strip wire it runs a lol better what could be any sugg… read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
15,567 satisfied customers
I noticed this past month when I had my boat pulled for
I noticed this past month when I had my boat pulled for indoor storage at Smith Boys marine here in Buffalo, and they placed her on a work rack for me to clean and wax thoroughly prior to going inside… read more
Tan
Tan
MerCruiser Certified Technician
Certified Marine Technician
10,957 satisfied customers
48 no fire to plugs how do you check kill switch. Engine
48 Johnson no fire to plugs how do you check kill switch … read more
Tan
Tan
MerCruiser Certified Technician
Certified Marine Technician
10,957 satisfied customers
I have a westerbeke 30b3 on my boat. The engine cranks but
Hi, I have a westerbeke 30b3 on my boat. The engine cranks but won't turn over. I changed peimary fuel filter and bled the engine to the cylinders. I'm getting plenty of fuel up until the cylinders bu… read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
15,567 satisfied customers
My engine will start by jumping solenoid but not by key
my engine will start by jumping solenoid but not by key replaced ignition swithch same thing ? … read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
15,567 satisfied customers
I have water mixed with engine oil on a 3406b. My boat has
I have water mixed with engine oil on a 3406b. My boat has been sitting between seasons for 10 weeks a I found a small hole in the muffler. I drained the fluid out of the engine what should I do next… read more
Cat Man
Cat Man
Vocational, Technical or Trade Scho
2,990 satisfied customers
What do I do. The control boxes or the units at the. And the
And the two toilets both work but nothing with the electro scan… read more
Boat Doc
Boat Doc
107 satisfied customers
I have 2 Volvo penta 5.7 gxis. One of them keeps getting
I have 2 Volvo penta 5.7 gxis. One of them keeps getting water in the cylinder heads, I replaced the manifold and risers. It's still happening. The oil is clean. Can you help?… read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
15,567 satisfied customers
Have a dragonfly 4 updated to latest now every time I turn
have a dragonfly 4 updated to latest now every time I turn it on it goes through a complete system check … read more
Matthew John
Matthew John
Cert II Electronic Engineering
41 satisfied customers
I have a 2008 Wellcraft 232 Fisherman powered with a 225 HP
I have a 2008 Wellcraft 232 Fisherman powered with a 225 HP Yamaha. Is there any reason I can't re-power with a new 300 HP Yamaha ? … read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
15,567 satisfied customers
I own a 1965 Hatteras Motoryacht with a pair of 1965 871N
I own a 1965 Hatteras Motoryacht with a pair of 1965 871N engines. The fuel tanks are in the keel and they each have their own separate ,pick-up tubes and 1000FG racors filters, then the engine filter… read more
Boat Doc
Boat Doc
107 satisfied customers
Im getting an over heat alarm when I run on hose with muffs.
im getting an over heat alarm when I run on hose with muffs. I noticed water coming out of the peephole when the motor is not running. is that a problem?… read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
15,567 satisfied customers
I am looking for improvements in my top end speed. I have a
I am looking for improvements in my top end speed. I have a fairly heavy bow rider. Its a 1992 Baja Islander 208 with a 350 mag. I have rebuilt the engine. It has 8.5 to 1 compression and a mild cam. … read more
MarineService8
MarineService8
34 satisfied customers
Twin 3406E 800 hp engines, under 700 original hrs Both
Twin 3406E 800 hp engines, under 700 original hrs Both produce STEAM which increases at higher rpm Clean oil analysis: no glycol..etc All gauges steady and normal Perfect performance except steam. All… read more
Cat Man
Cat Man
Vocational, Technical or Trade Scho
2,990 satisfied customers
I have a 1998 9.9 2 stroke tiller manual start mercury
I have a 1998 9.9 2 stroke tiller manual start mercury outboard. For years it gave me no problems. I pull the choke plunger out 3 times and start it right away. It runs about 30 seconds , then dies an… read more
Tan
Tan
MerCruiser Certified Technician
Certified Marine Technician
10,957 satisfied customers
Suzuki df 70 serging at 2800 RPMs. I have replaced the
I have replaced the Injector pump and spark plugs .plugs showed signs of too rich fuel .Tried it out started fine but serges At 2800rpms … read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
15,567 satisfied customers
Bought a used 2001 Sea-Doo Challenger 189 Bombadier and took
Bought a used 2001 Sea-Doo Challenger 189 Bombadier and took it out today for the first time and the hull completely filled with water! Drain Plus were in … read more
Boat Doc
Boat Doc
107 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