86 mercruiser 4 cyl cant get a spark

[mikeb62]

no spark. coil, plug, wire good. Need some ideas what it could be. there is a wire coming off the - side of the coil going to the top of the engine to a metal switch. Does anyone know what that is? the other wire on the - side goes to the distibutor, and there are two wires going to +.

 

[hoot]

Re: 86 mercruiser 4 cyl cant get a spark

do you have a volt meter and can check volts at the + post of the coil? the two wires at the + post are probably from the resistance device (wire or ballast) and the direct 12 volts for starting. don't know about the 'switch'. if this switch grounds out the coil, you will get no spark. do you have a safety kill switch and tach?<br />and how did you check the coil?

 

[mikeb62]

Re: 86 mercruiser 4 cyl cant get a spark

chnged the coil. the boat does have a tack and volt meter. the switch is on top of valve cover hooked to the throtle cables. we did however turn the ignition on and move the switch back and forth and got a spark. so we are thinking its some sort of kill switch. But we bypassed that switch and it still did not work. I am very knowledgable with car motors but know little about boats.

 

[hoot]

Re: 86 mercruiser 4 cyl cant get a spark

let me clarify the volt meter. do you have a handheld meter that you can use to check voltages and resistances? and what type of engine/boat is this? has it ever run? do a basic check of points/condensor/battery/wiring connections,...if you take the switch out of the circuit by removing the terminal from the post, what happens?

 

[mikeb62]

Re: 86 mercruiser 4 cyl cant get a spark

ok i have a hand held volt meter. all basics are checked and are correct. the switch im refering to is number 18 on this diagram <br /><br /> http://mercruiserparts.stemtostern.com/partsimages/CRUISER/41261/39.gif <br /><br />its is a 2.5 mercruiser in a 18' 87 cobia monte carlo. the boat ran perfect before parked for 2 years. we have tried bypassing that switch, disconnecting the lead to the coil form that switch. but also what was very odd is when i tested the coil i was getting ++ to both sides of the coil. so im thinking that that switch is either bad or hooked up incorrectly. but like i said if we take that switch and hit it back and forth we get a spark.

 

[hoot]

Re: 86 mercruiser 4 cyl cant get a spark

that is your shift interupter switch. it grounds out your coil quickly to let the gears disengage. i think it should only move when you are coming out of gear. the roller should be centered in the notch during normal operation. they don't normally give much trouble, but the cable does. one wire should go to the switch from the coil and the other from the switch to ground. if you disconnect either wire, the switch will be removed from the starting circuit. on my coil, i get 7 to 8 volts with the key in the on position and will get 12 volts during start. i read this value from either small terminal back to ground. resistance thru my coil is ~1.5 across the small terminals, and ~9000 from the small + to the secondary post. where do you see or check the spark?

 

[mikeb62]

Re: 86 mercruiser 4 cyl cant get a spark

we just useing it like a car. taking the coil wire off the distubutor cap and putting a spark plug on it then holding it to metal on the block. also have another question. the circuit breaker ( red button) should that be were you cannot push or pull it at all?

 

[hoot]

Re: 86 mercruiser 4 cyl cant get a spark

circuit breaker reset button. does not move unless breaker is overloaded.

 

[mikeb62]

Re: 86 mercruiser 4 cyl cant get a spark

ok. then i am just baffled. but im sure its something simple. going to try to get a friend that knows allot about marine motors to come over and help me out. thanks for the help though

 

[hoot]

Re: 86 mercruiser 4 cyl cant get a spark

if you find what happened, be sure to post the solution. there is another post with no spark going on also.

 

[mikeb62]

Re: 86 mercruiser 4 cyl cant get a spark

ok. sure will.

 

[Boatin Bob]

Re: 86 mercruiser 4 cyl cant get a spark

Mike...do you have points or does this have some kind of Thunderbolt ignition, if you were able to get a spark by hitting the interupt switch then you were charging/discharging the coil, thats what the points or TB should be doing. ps...if the ground is open on the coil then you will see +volts on the + and - sides of the coil.

 

[Blk-n-Blu]

Re: 86 mercruiser 4 cyl cant get a spark

Is the Safety cut off lanyard hooked up (if so equipped)

 

[mikeb62]

Re: 86 mercruiser 4 cyl cant get a spark

yeh its a points distibutor. And thats what I was thinking so im going to chng out the points see if that does the trick. And i dont know what this is ----> "Is the Safety cut off lanyard hooked up"

 

[Boatin Bob]

Re: 86 mercruiser 4 cyl cant get a spark

You may not have the safety lanyard switch, it's usually got a cord on it that some people like to attach to their wrist, if you pull the cord the switch trips and kills the ignition, it's wired to the + ignition wire so it kills power to the coil. Similar to the Neutral safety switch in your contol box

 

[mikeb62]

Re: 86 mercruiser 4 cyl cant get a spark

oh ok. Have that on my jetski. But no dont have one of those on the boat.

 

[hoot]

Re: 86 mercruiser 4 cyl cant get a spark

i would use a shotgun approach and replace everything ignition related, points, condensor, cap, rotor, coil,...and check all the connections. 2yrs could allow corrosion to build up on the terminals.

 

[mikeb62]

Re: 86 mercruiser 4 cyl cant get a spark

yeh thats what i was thinking. hopefully that will do the trick im ready to get out on the water. football season just started and Id rather drive the boat to the games

 

[1996Starcraft]

Re: 86 mercruiser 4 cyl cant get a spark

I had this problem at the beginning of the season and I about shot myself when I saw the safty lanyard switch was open. 1986 may be before "safety" was a concern to us. My cord just hangs down.

 

[Ralor]

Re: 86 mercruiser 4 cyl cant get a spark

I had this problem at the beginning of the season and I about shot myself when I saw the safty lanyard switch was open. 1986 may be before "safety" was a concern to us. My cord just hangs down.