mercruiser 140 I/O Ignition Problem

[chevydan04]

I have a 1985 seasprite bowrider w/ a mercruiser 140 I/O, I am new to boats, but have worked on cars for many years.

So the problem I have is that I am not getting a spark from the coil, but I don't want to go replacing something until I have eliminated most other problems.

any help would be great.

Pictures are awesome

Engine serial # A368475

 

[Don S]

Re: mercruiser 140 I/O Ignition Problem

To start with, head up to the Adults Only Sticky at the top of this forum and start reading. There is a section there for troubleshooting a points system. You can also download the OEM service manual for your engine and drive..... for free.
Then, you are armed and ready to do battle with your problem.

Probably going to find that you need a set of points (a full tunup actually) because the points become glazed over during winter.

 

[ziggy]

Re: mercruiser 140 I/O Ignition Problem

Probably going to find that you need a set of points (a full tunup actually) because the points become glazed over during winter

fwiw. Lime Time wouldn't start this spring. never really diagnosed why. just hit the points with some emery cloth. started right up then. likely glazed over i suppose. after starting and blowing out the fogging oil. then i put in new points. along with all other minor tune up items.

i also go around and clean up as many contacts as i can find to take apart and clean up. you'd be amazed how tarnished the connections are after only one year and how new and shiny they become after cleaning them up with some emery cloth... connections do tarnish over the course of time from last springs summerization..

 

[achris]

Re: mercruiser 140 I/O Ignition Problem

Do you have conventional points, or the DDIS (Digital Distributorless Ignition System)?

Chris.........

 

[chevydan04]

Re: mercruiser 140 I/O Ignition Problem

thanks for the advice I will keep you all updated. I am actually thinking my coil is bad but I will clean all the contact points and see what happens. I am getting 12 volts DC to the coil. Just no spark out of the coil.

Also I do not have a digital ignition system, I have found no evidence of a computer onboard my boat. Other than my fish finder

 

[achris]

Re: mercruiser 140 I/O Ignition Problem

Check that you have 12 volts on the -ve side of the coil with the points open.

If you don't, disconnect all the wires from the -ve of the coil and check again...

If you have 12volts, put the wires back on, one at a time. It could be a faulty condenser or a faulty tacho...

If you still don't have 12 volts on the -ve side of the coil with all the wires off, then it is definitely the coil.

Chris.......

 

[chevydan04]

Re: mercruiser 140 I/O Ignition Problem

I only have had a total of about 30 min's of troubleshooting after my last post, (the wife doesn't want me working on it until my weekend mon-wed)

Today I discovered that when testing my coil tower to + terminal I get 10.23 ohms at a measurement of 20K. Same reading from - terminal to coil tower. (I performed this test with both + and - terminals disconnected from their perspective wiring)

So I am thinking my coil isn't the problem not sure.

What are your thoughts?

Also I removed the gray wire and tested for spark no spark.

I also am able to get 12 DC at both terminals on the coil, when I put my multimeter on the terminal and touch it to a ground.

Also removed the spark plugs and they seemed to have alot of fuel on them and they were covered in black gunk.

My compression is good.

Any help or advice would be appreciated guys.

 

[cooter2506]

Re: mercruiser 140 I/O Ignition Problem

Did you check your points like Don suggested. IM betting on that its points also.

 

[chevydan04]

Re: mercruiser 140 I/O Ignition Problem

I went out to the boat for another 15 mins... took the dist. cap off and inspected the point, and the condenser. They both look brand new. The person I bought the boat off said he had just replaced them about 1 week ago.

I am thinking I need to do the dwell test, Luckily I have a friend with a dwell meter so I will borrow it from him. Although I do not see a way to really adjust the dwell. but I am sure I can figure it out.


How does the fuel system tie into a no spark situation?


I apologize for not mentioning that I have owned the boat for less than a week. It is a real nice boat. The motor hardly looks worn. And when I crank it I get good compression, and it sounds really healthy. But I have not heard it run yet, because of my no spark issue.

 

[chevydan04]

Re: mercruiser 140 I/O Ignition Problem

I have not checked the neutral safety switch. But would the engine turn over if it were bad?

I do now it will turn over when the shifter lever is engaged

 

[turbinedoctor]

Re: mercruiser 140 I/O Ignition Problem

Check that you have 12 volts on the -ve side of the coil with the points open.
If you don't, disconnect all the wires from the -ve of the coil and check again...

If you have 12volts, put the wires back on, one at a time. It could be a faulty condenser or a faulty tacho...

If you still don't have 12 volts on the -ve side of the coil with all the wires off, then it is definitely the coil.

Chris.......

You can also check the volts on the neg side of the coil with the points closed, if you still have 12 volts then the points are not making contact and you wont get any spark.

It has been said several times in this tread to check the points. Even if they look new and the previous said they were replaced, they can still be faulty.

Durwood

 

[chevydan04]

Re: mercruiser 140 I/O Ignition Problem

yes yes yes... victory...

Ok so I cranked the engine and got some nice blue spark.

it ended up to be the wire leading from the distributer it was grounding out... It wasnt' in its proper holding place, so I adjusted it, and bam I was able to get spark.

Thanks for your help guy's.

I learned alot from your replies and also the ADULTS ONLY trouble shooting.

I have never dealt with a breaker points ignition before, only the electronic type. so I was greatly confused, but I now somewhat understand it.

 

[achris]

Re: mercruiser 140 I/O Ignition Problem

Do I read it right? Did you buy a boat WITHOUT hearing the engine running? And without a water test?

Brave man!!!

 

[turbinedoctor]

Re: mercruiser 140 I/O Ignition Problem

I was thinking that too but didn't want to go there.

Durwood

 

[chevydan04]

Re: mercruiser 140 I/O Ignition Problem

I'm Air Force and the person I bought the boat off is retired Air Force kind of a trust I suppose.

 

[fixb52s]

Re: mercruiser 140 I/O Ignition Problem

I am retired a Air Force maintainer, but I still would expect someone to run anything I might have for sale. At least it all worked out for you here, but there are a lot of horror stories out there about Air Force folks getting burned. Do you have those "We finance military because we are retired military" car lots just outside the main gate? All because someone is retired doesn't mean they are honest, it makes a good sales pitch. I cannot even begin to count the number of troops that were burned while I was a Flight Chief. Sometimes the 1st Shirt could make a call fixing it, but most times it is buyer beware.

You sound like a Jet Mech, and I assume you see the need for QA and Supervision in your shop. Most troops do their job by the T.O., but you have a few who do not. While a retired AF person might have been brought up with the "service before self" mentality, a follow up is still called for. I can say that even though "Joe" might have replaced that fuel control on the TF-33, it will be double checked. Take the same mentality for anything you might be interested in, and you will never get burned. And if it is something you have little knowledge in, take someone with you who does have that knowledge.

OK, off the soapbox now.....

 

[chevydan04]

Re: mercruiser 140 I/O Ignition Problem

I picked the boat up for $700. Galvanized trailer in good condition, boat in great condition, checked compression, oil, and turned the motor over. That was enough for me. I have about $900 with titleing and registration and some parts, and the boat works great.

The man told me before I came that he couldn't get the boat to start and I could come by some other day when it did. originaly asking $1000, I asked how much if it didn't run when I picked it up, so he said $700.

All in all I am happy with the outcome.

I have been burned in the past, by dishonest people.

Did I mention I have also been a used car salesmen. (learn alot about reading people, you can learn alot from someone just by asking them key questions and looking them in the eye.)

Yes I am a maintainer, on a big old airplane.

I would say that most people in the AF have great integrity, and I do not deal with dealerships of any kind, they are trained professional sleeze balls.

Took out the boat today it runs amazing, and planes out quickly.

Thanks again for your help and input.

I am new to boating but the boat has replaced my motorcycle... so I am sure I will need some of your help in the future.