3.0L 4cyl no spark

8x56mn

Petty Officer 2nd Class
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Feb 7, 2006
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124
Hello, I'm new hear and new to boats in general. I have just acquired a 1989 Sea Ray with a 3.0L I/O engine and drive.<br />My problem is I can't get spark to the plugs. Now mind you I'm an engineer, but no mechanic OK.<br />I have replaced the plugs, the plug wires, rotor, points, condenser , cap, and coil and still no spark. What can I do, should I just take the thing to a shop and be done with it or try to fix it myself. It's cold here and none of the shops want to turn on their water until spring so they won't do anything until then.
 

Haut Medoc

Supreme Mariner
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Jun 29, 2004
Messages
10,645
Re: 3.0L 4cyl no spark

Welcome to iboats.....Do you have 12 volts at the + side of the coil with the key on? I would look for a bad ignition switch/bad connection with a test light or digital volt meter.....JK
 

Laddies

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Sep 10, 2004
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Re: 3.0L 4cyl no spark

Ch for power at the coil and ck the shift interupter switch
 

Haut Medoc

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Re: 3.0L 4cyl no spark

What laddies said too about the shift interrupter switch....Also some boats have a kill switch lanyard....JK
 

8x56mn

Petty Officer 2nd Class
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Feb 7, 2006
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Re: 3.0L 4cyl no spark

Yes I have to get a test light, plan to do that On the way home today. Thanks
 

Haut Medoc

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Jun 29, 2004
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10,645
Re: 3.0L 4cyl no spark

If you do not have 12 volts at the + side of coil, the next place to look is terminal "B" on the ign. switch....Should be 12v there....JK
 

8x56mn

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Feb 7, 2006
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Re: 3.0L 4cyl no spark

One other question, are these motors reliable, can I expect them to start every time generally once there tuned up or will they let me down out on the lake and have to be towed home. Like I said I'm new to boats, but plann to retire and do a little fishing. I live on Seneca Lake and the lake offers some nice fishing. I got my slip reserved and looking forward to spring.
 

DHPMARINE

Captain
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Dec 16, 2003
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3,688
Re: 3.0L 4cyl no spark

3.oL is a workhorse of an engine when in good shape.Just a quick note : the shift interrupter switch will kill the spark,if it is activated.The neutral safty switch ( in the remote control) will keep it from cranking.If you do get spark and put water to it BE SURE to drain the manifold and block.<br /><br />DHP
 

Haut Medoc

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Jun 29, 2004
Messages
10,645
Re: 3.0L 4cyl no spark

What type of drive?....I'm assuming Mercruiser......The engine itself should be very reliable if it was properly cared for.....You should do some looking in the 'search' function at the top of the page....If you have no info on this boats maintenence history, there are other maintenence issues that probably be addressed.....Especially the drive shaft bellows......Any info from Don S., Rodbolt & Bondo you can pretty much take to the bank ;) :) Good luck with your search, there is alot of info there.... Btw, the shift interrupter switch will kill the spark if it is stuck, I was thinking about the neutral safety switch, in the above post.....I have a hard time doing three things at once.....If that switch is stuck = no spark......Look at the shift plate on the engine, where the cables to helm, cables to transom go.....Let us know how you made out.......JK BTW, DHP is pretty smart too :D
 

tashasdaddy

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Nov 11, 2005
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51,019
Re: 3.0L 4cyl no spark

if you don't have one get the proper mercruiser manuals, and listen to the guys here they will save you alotta grief and $. i shoudda listened 1st. i learned the hard way.
 

8x56mn

Petty Officer 2nd Class
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Feb 7, 2006
Messages
124
Re: 3.0L 4cyl no spark

Yes it's a Merc Cruser. Please tell me more about the "shift interupter", where is it located. My boat has a single handle throttle with a square button on the lower end that you push in to dissengage the drive and then you can push it forward and backward to force gas into the carb. like the old cars when you pumped the gas peddle a few times. The engine turns over fine, I just don't get spark.
 

Haut Medoc

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Jun 29, 2004
Messages
10,645
Re: 3.0L 4cyl no spark

The shift interrupter switch is on or near the engine (possibly attached to the exhaust manifold), where the cable from the helm meets the cable that goes out of the transom......Without depressing the button you describe shift into fwd.....If you have an assistant, better yet, you will see what part moves......I have the older style, but if memory serves right, on yours the little wheel should be in the detent.....The cable that goes to the outdrive probably needs replacing if it will not return to this position after shifting.....The purpose of this switch is to kill the engine for a split second to allow the clutch dogs in the drive to disengage....<br />Just loook where the cables come together & it should be obvious.....Hope this helps....Maybe someone can post a link or pic......JK
 

whywhyzed

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Feb 1, 2005
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1,871
Re: 3.0L 4cyl no spark

Anybody suggest checking to see if the distributor is turning? I aint reading all that above...<br /><br />with the distributor cap off, crank the engine and make sure the pointer's going roundy round...
 

KRS

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Re: 3.0L 4cyl no spark

Welcome, forget the boat... what does 8x56mn mean?
 

8x56mn

Petty Officer 2nd Class
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Feb 7, 2006
Messages
124
Re: 3.0L 4cyl no spark

Thanks I will check that tonight. When I picked up a test light on the way home last night I checked the following; with the key on, attached one end of the test light light to the ground on the battery and then touched each side of the coil and got a light each time I then pulled of the DC and touched the points and got a lightmwhich I thinks tells me the wire from the coil to the points is OK,, I then bumped the starter and the rotor turned thats OK. I tried to open the points by hand thinking I would get a spark, but got nothing.
 

8x56mn

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Feb 7, 2006
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Re: 3.0L 4cyl no spark

8x56mn is my handle, I collect Mannlicher Schoenaur's and 8x56 is a calibre, OK:)
 

Don S

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Re: 3.0L 4cyl no spark

Have you set the gap properly on the points?
 

8x56mn

Petty Officer 2nd Class
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Feb 7, 2006
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Re: 3.0L 4cyl no spark

Well I thought that by spreading or opening the points by hand should show a spark/ark right. I'm going to check the points closely and clean them off with a point file to be sure tonight and try to get them to ark. Man this is a learning experience for sure, I really appreciate all the help. Thanks
 

Don S

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Re: 3.0L 4cyl no spark

IF you put in new points, you don't need to file them. Besides, filing is a "get home" process so you can replace them. <br />
Well I thought that by spreading or opening the points by hand should show a spark/ark right
Depending on how you checked them, if you used as screw driver between the 2, the screwdriver would have made the path.<br />Open the points and check with your test light.<br /><br />Do you have a service manual?
 

8x56mn

Petty Officer 2nd Class
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Feb 7, 2006
Messages
124
Re: 3.0L 4cyl no spark

No not yet, I plan to recheck that tonight, but that would not explain why they would not spark when they were spread open by had from a closed position. Is that a correct statement?
 
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