No spark from coil. 3.0 181 4cyl. merc. i/o

[chmath]

I have a 89' 3.0L 181 4cyl 130hp mercruiser i/o<br />and have not been able to get it to start. I have replaced the coil and done a tune up of the dist. and still nothing. Battery is also brand new and has over 12voltson it. all connections are good. I have just about lost my mind trying figure out why this will not fire.......Any help ?????

 

[John Boelte]

Re: No spark from coil. 3.0 181 4cyl. merc. i/o

There are three wires (two terminals) on the negative (forward) side of the coil. One wire goes to the distributor, one to the tachometer, and I'm not sure where the other goes; anyway, disconnect the terminal with the two wires in it and see if you get spark then. I ran into the same problem yesterday and got it running by removing those two wires.<br /><br />Does anyone know where the third wire goes? A safety device maybe?

 

[chmath]

Re: No spark from coil. 3.0 181 4cyl. merc. i/o

Thanks for the tip ...Tried and still nothing???<br />I have tried getting some help from local boat shops but all they say is bring it in for $70 per hr. labor and they trouble shot it...I understand that everyone needs to make a living but I hate to pay that kind of money for what seems to me cant be that big of a problem. It is more than likely something simple that I can't figure out what it is.

 

[Northern Eclipse]

Re: No spark from coil. 3.0 181 4cyl. merc. i/o

You state you completed a tune-up of the dist, did you replace the points and condenser? are the point gapped correctly, are you getting fuel to the carb. Try cleaning the points with a fine emery cloth, new or old they can get a glaze on them, clean gap and see if she fires.

 

[chmath]

Re: No spark from coil. 3.0 181 4cyl. merc. i/o

Points and condenser where replaced but I have not checked for glazeing...I was told just to swap out parts and everything would be the same . The marine shop that I purchased the kits from never said anything about setting the GAP...Does anyone know what the correct GAP should be? And if so how do you set them? Thanks for your help. <br /><br />The motor is a 89' 4cyl. 130hp 181ci 3.0L mercruiser

 

[Boatist]

Re: No spark from coil. 3.0 181 4cyl. merc. i/o

Gap should be .018" with the cam on top of the lobe. If you have a dwell meter dwell should be 31 to 34 degrees. To adjust loosen mounting screws and move points closer or farther away. Usually have a notch you can put a screwdriver in to aid in adjustment. also make sure have spring tension tryiny to close points. make sure wires are hooked up.<br /><br />All this info should be in your shop manual.

 

[hoot]

Re: No spark from coil. 3.0 181 4cyl. merc. i/o

check the basics first. are you getting fuel to the engine? push throttle and see if gas is squirting into the carb. are you getting spark? pull a plug wire, hold it close to plug end, crank engine. does spark jump across to plug? check kill switch. can you use a volt meter and get volts at terminals on coil?<br /><br />to john b; the third wire most likely goes to the shift cut out switch located on the shift/throttle cable plate. if this switch goes closed, boat will not start. and i have a wire on my coil for the kill switch, not sure if it is on the + or - side.

 

[chmath]

Re: No spark from coil. 3.0 181 4cyl. merc. i/o

Thanks to all who have given me tips....I ran a jumper wire from the battery directly to the coil + side and it fired right up..Turned it off right away and disconnected the wire and it started on the first turn of the key without the jumper on..I'm not sure why it worked or what caused it to not work but it seems to be O.K. now...Of course I had the muffs on at all times just in case.<br /><br />Engine started and is running a little rough but I need to set the GAP correctly..<br /><br />How can I tell if the cam is on top of the lobe to set the gap? I don't have a dwell meter.

 

[hoot]

Re: No spark from coil. 3.0 181 4cyl. merc. i/o

remove distributor cap. bump key switch. watch the points and cam that opens and closes the points as motor turns over. you will see when they are open. my distributor does not have a way to adjust dwell, just gap. be sure the key switch is off when you put the feeler gage in the gap or sparks may fly. and remeasure gap after you tighten the screw. sometimes the gap will close as you torque the screw down. i would do many trial starts on muffs to be confident that the problem has gone away. seems like boat was not getting any volts at coil to start. the volts on some engines come from a slave/start solenoid or solenoid located on the starter.

 

[chmath]

Re: No spark from coil. 3.0 181 4cyl. merc. i/o

I will try to set the GAP aas soon as the rain stops...It does have a starter solenoid seperate from the starter but it is also new...I'm not sure what the problem is but I sure would like to know before going back to the lake...

 

[Boatist]

Re: No spark from coil. 3.0 181 4cyl. merc. i/o

Adjusting the gap will change the dwell. You can normaly turn the motor by hand if you take the plugs out. Turn the alternator with a wrench and a tight belt and it will likely turn engine so you get points cam on top of the lobe and then adjust the gap.<br /><br />If you have trouble starting again check voltage on the plus side of the coil. While cranking it should be same voltage as battery when cranking. If it is much lower then wire from the starter solenoid may not be wired correctly.

 

[chmath]

Re: No spark from coil. 3.0 181 4cyl. merc. i/o

Thanks everyone for your help.....Boat running and starting great....