Impossible to get spark!!

[brinkmannap]

Ok...so I have a 1984 mercruiser 140 inboard motor in an Imperial open bow. I rebuilt the motor and put the motor back in. Hooked everything up and I'm not getting any spark. I've tried everything. Motor is grounded good, alternator and everything is wired correct, brand new cap, rotor, and points, including condensor, brand new coil, new plugs and wires. I've tried everything. Coil is wired up correctly. Still getting no spark. I even took a plug and hooked it to the coil wire to see if I'm getting anything out of the coil. Nothing. I checked all the wiring based upon a wiring schematic from a mercruiser repair manual. Everything looks good...but still no spark. Could some help real bad. I have a guy coming to look at the boat to buy it...and he's expecting a boat that runs! Thanks in advance.

 

[T-Bone Coug]

Re: Impossible to get spark!!

Are points gapped properly, and do you have voltage at the coil. Do a search and you'll find lots of info on troubleshooting a points ignition system.

 

[brinkmannap]

Re: Impossible to get spark!!

Points are gapped at 5mm or .22 on a feeler guage. I have a constant voltage wire ( purple ) going to the + side of the coil, a purple and red wire coming from the starter going to the + side of the coil, a grey ( tach ) wire which actually i believe looks to be coming from the neutral safty switch along with the black wire from the distributor going to the - side of the coil. There is power witht the key switch on to the + side of the coil and the - side.

 

[billy4hp]

Re: Impossible to get spark!!

Points are gapped at 5mm or .22 on a feeler guage. I have a constant voltage wire ( purple ) going to the + side of the coil, a purple and red wire coming from the starter going to the + side of the coil, a grey ( tach ) wire which actually i believe looks to be coming from the neutral safty switch along with the black wire from the distributor going to the - side of the coil. There is power witht the key switch on to the + side of the coil and the - side.

If what you wrote is actual, your points are never closing. The gap should be around .014 to .017 give or take a few thousandth (refer to your manual for actual point gap).

 

[JustJason]

Re: Impossible to get spark!!

1. point gap will get you close, but you really need to set them with a dwell meter.

2. Disconnect the tach and see if the spark comes back.

 

[cr2k]

Re: Impossible to get spark!!

Do you have a lanyard safety switch? If so maybe it is in the off position.

If not the problem, disconnect everything from the - side of the coil except the distributer wire.

If that don't work run a jumper from the +battery to the +coil and give it a go.

if that works you will know the problem is in your wiring and not the ign system.

 

[Fishermark]

Re: Impossible to get spark!!

One more thing to try in addition to the above. Sometimes new points have to be cleaned. They can get a coating on them. With the key off, use some electrical contact spray and a clean rag and wipe the surface of the points. Then try to start again.

 

[brinkmannap]

Re: Impossible to get spark!!

Thanks everybody for your input. I have spark now. Its backfiring through the carb. I thought it would be 180 deg off at the dist. I rotated it and its still not right. #1 cyl at tdc, both valves closed. rotor pointed towards the #1 cyl. Hmmmm....still not firing right. plug wires and order are all correct. firing order is 1342. Any ideas? Thanks

 

[Bondo]

Re: Impossible to get spark!!

Its backfiring through the carb.

Ayuh,... It could be a Lean condition...

 

[pogi]

Re: Impossible to get spark!!

What did you do to get the spark back at the coil? I'm having kinda the same problem.

 

[Don S]

Re: Impossible to get spark!!

pogi, it doesn't really matter what his problem was, it's now what is causing your problem. I would suggest you start a new thread of your own, and include what engine, drive, year, model etc. you have.

 

[bomar76]

Re: Impossible to get spark!!

rotor pointed towards the #1 cyl. Any ideas?

This has come up numerous times.
When you say the rotor points at Cylinder #1.......you know that means the tower in the dizzy cap for cylinder #1 NOT the actual cylinder, correct?


Been done many times by others.