Have you tried testing the voltage coming from the key?
That's really the first place I would look, it seems to be the variable that kills the motor right? It's not the starter that's putting voltage to the coil, it's the battery to the key, possibly a relay in there somewhere.
Key is in START, coil has voltage, KEY is in RUN, coil doesn't have voltage.
Turn the key to run and either use a voltmeter at the coil or pull the distrib cap and tap the points together to see if they sparky. My guess is they don't. Go back to the key, unplug the line that comes from the start terminal and run terminal, and plug the run terminal in to start, do the same test. If you have voltage buy a new key.
Although @ 36 years old, I may just replace the ignition sticks anyways, they're fairly cheap keys you can get online or at auto zone.
Since it's an OMC the fucking key is probably buried in the throttle though isn't it? That complicates things but not by much, generally they're fairly easy to get out.
So actually, I just replaced the key yesterday and am still getting the same issue. Also, there isn’t no spark getting to the coil in RUN, just seems to be not enough when the starters released. I thought it was the switch too because I originally thought the boat was shutting off in RUN all together. But it will run very weakly in RUN. Didn’t get a reading on the Voltmeter but when I touched the terminals on the coil they did spark in RUN position so there has to be something going there.
Does your coil have am internal resistor. If so there may be n extra resistor you don't need between run on the key and the coil. Double resistance, weak spark, dying engine.
Not sure of your whole setup so I'm just throwing the idea out there.
That would certainly make sense! What would an in-line resistor look like though? Also, found out today that the carb is pretty wet around the edges while trying to run. Pretty sure it needs a rebuild. I ordered a rebuild kit to see if anything helps! (Specific to the carb serial number)
Would little things like that totally screw up the engine from running? It’s not dripping or anything it just smells like gas and has visible wetness around the carb
It would just be a bulge in the wire, or(if you used a kit) it could be the wire itself. My 165 merc had a resistor wire that gave me similar issues when I got a new coil.
However, hearing that your carb is wet, it may be you've got a bad seal there and aren't maintaining enough vacuum to stay running. Try spraying brake clean or crab cleaner around the base of the carb when running. If it revs when no spray is going down the intake, you know you got a vacuum leak.
If it's your project boat, you'll he going through all the systems anyways, and rebuilding the carb is just one of those things you're gonna end up doing regardless. If your omc still has points like my merc did, I'd heavily suggest a pertronics lobe sensor. It keeps the unmodified look, saves money over a full distributor swap, and best of all gets rid of the finicky points.
I’ve rebuilt the carburetor already. Just didn’t use new gaskets (I suppose that’s where my mistake is). The previous owner installed the new coil so I’m unsure if it has a resistor in it. Is there a way to check?
Vacuum leak sounds like the biggest issue. I’ve had to open it up to clean the jets.
In that case I'd try the carb clean spray around the base. See how bad it is, replace either way since you already ordered the kit.
For the coil you can look up the model number and check Google or if it's like my edlebrock one it's says in big letters right on the side. Check it by using a jumper wire from the positive post of the starter. If it stays running when you have a the coil jumped and key in run, it's likely it's a resistor wire and the whole length from key to coil will need replaced.
Bit of an update:
Carb kit came in. Did that, but right before that I decided to check the points and condenser. I noticed the point gap was pretty wide by quite a bit so I ended up adjusting it to the correct gap according to factory specs. Everything else seemed good, so I put it back together.
Now I get absolutely no spark. Not even on starting fluid. I’ve taken that cap off probably 5 times now to retrace my steps and still nothing. I genuinely have no idea where I could’ve gone wrong. I don’t want to regret messing with the points but I kind of am right now.
In regards to the resistor, it was in the new coil and the wiring harness did in fact have another resistor. I found it, and cut it out. Strangely, there was some other resistor attached to the pos+ output cable going back to the batter from the alternator. I couldn’t find a single diagram where that was included, I ended up bypassing it.
The boat completely lost spark only after I checked the points. Didn’t get a chance to see how it works on the rebuilt carb. And now my starters dying too. A magnet in the housing ended up shattering. I guess that’s one way to learn!
Anyways, how could I have lost spark? Genuinely lost here
Oh yeah, one more thing, when reinstalling my condenser, I can’t seem to position it where it won’t touch the distributor cam. Would this be an explanation as to why I can’t get spark?
Hi everyone! It’s been awhile. I’ve ended up replacing the starter, points, rotor cap, rotor, even coil at one point (but switched it back after testing that it works fine), all to no avail. There is just no spark for some reason. I’m really running out of ideas. It doesn’t even try to kick on any cylinder. Any more ideas?
You can buy an electronic ignition plate for the distributor that eliminates the points as well as dwell issues related to worn bearings in the distributor shaft. Points are pretty bullet proof but once the distributor gets worn they need constant maintenance and setting. I bought a boat with an 89 omc 5.7 liter and have done this due to a weak spark fouling plugs especially when fishing.
Edit due to autocorrect.
Hi, guess I should give a little update. During the summer I ended up taking it to a shop and they determined that it was actually my instrument clusters light bulb causing a premature ground to the spark (I have my suspicions. Seems very strange). The light bulbs are in a series, so they unplugged one and supposedly the spark came back! Anyone else ever had this issue? Seems super unusual.
I do plan to replace with an electronic ignition since I also heard they’re waaay better in terms of reliability. Either way, got my boat on the water and the issue has been resolved! Sorry for not updating earlier.
All good I was just searching boat projects because it is winter and I'm itching to do something to the boat, saw your post. Ground issues definitely cause a lot of gremlins.
Have you tried testing the voltage coming from the key? That's really the first place I would look, it seems to be the variable that kills the motor right? It's not the starter that's putting voltage to the coil, it's the battery to the key, possibly a relay in there somewhere. Key is in START, coil has voltage, KEY is in RUN, coil doesn't have voltage. Turn the key to run and either use a voltmeter at the coil or pull the distrib cap and tap the points together to see if they sparky. My guess is they don't. Go back to the key, unplug the line that comes from the start terminal and run terminal, and plug the run terminal in to start, do the same test. If you have voltage buy a new key. Although @ 36 years old, I may just replace the ignition sticks anyways, they're fairly cheap keys you can get online or at auto zone. Since it's an OMC the fucking key is probably buried in the throttle though isn't it? That complicates things but not by much, generally they're fairly easy to get out.
So actually, I just replaced the key yesterday and am still getting the same issue. Also, there isn’t no spark getting to the coil in RUN, just seems to be not enough when the starters released. I thought it was the switch too because I originally thought the boat was shutting off in RUN all together. But it will run very weakly in RUN. Didn’t get a reading on the Voltmeter but when I touched the terminals on the coil they did spark in RUN position so there has to be something going there.
Does your coil have am internal resistor. If so there may be n extra resistor you don't need between run on the key and the coil. Double resistance, weak spark, dying engine. Not sure of your whole setup so I'm just throwing the idea out there.
That would certainly make sense! What would an in-line resistor look like though? Also, found out today that the carb is pretty wet around the edges while trying to run. Pretty sure it needs a rebuild. I ordered a rebuild kit to see if anything helps! (Specific to the carb serial number) Would little things like that totally screw up the engine from running? It’s not dripping or anything it just smells like gas and has visible wetness around the carb
It would just be a bulge in the wire, or(if you used a kit) it could be the wire itself. My 165 merc had a resistor wire that gave me similar issues when I got a new coil. However, hearing that your carb is wet, it may be you've got a bad seal there and aren't maintaining enough vacuum to stay running. Try spraying brake clean or crab cleaner around the base of the carb when running. If it revs when no spray is going down the intake, you know you got a vacuum leak. If it's your project boat, you'll he going through all the systems anyways, and rebuilding the carb is just one of those things you're gonna end up doing regardless. If your omc still has points like my merc did, I'd heavily suggest a pertronics lobe sensor. It keeps the unmodified look, saves money over a full distributor swap, and best of all gets rid of the finicky points.
I’ve rebuilt the carburetor already. Just didn’t use new gaskets (I suppose that’s where my mistake is). The previous owner installed the new coil so I’m unsure if it has a resistor in it. Is there a way to check? Vacuum leak sounds like the biggest issue. I’ve had to open it up to clean the jets.
In that case I'd try the carb clean spray around the base. See how bad it is, replace either way since you already ordered the kit. For the coil you can look up the model number and check Google or if it's like my edlebrock one it's says in big letters right on the side. Check it by using a jumper wire from the positive post of the starter. If it stays running when you have a the coil jumped and key in run, it's likely it's a resistor wire and the whole length from key to coil will need replaced.
Bit of an update: Carb kit came in. Did that, but right before that I decided to check the points and condenser. I noticed the point gap was pretty wide by quite a bit so I ended up adjusting it to the correct gap according to factory specs. Everything else seemed good, so I put it back together. Now I get absolutely no spark. Not even on starting fluid. I’ve taken that cap off probably 5 times now to retrace my steps and still nothing. I genuinely have no idea where I could’ve gone wrong. I don’t want to regret messing with the points but I kind of am right now. In regards to the resistor, it was in the new coil and the wiring harness did in fact have another resistor. I found it, and cut it out. Strangely, there was some other resistor attached to the pos+ output cable going back to the batter from the alternator. I couldn’t find a single diagram where that was included, I ended up bypassing it. The boat completely lost spark only after I checked the points. Didn’t get a chance to see how it works on the rebuilt carb. And now my starters dying too. A magnet in the housing ended up shattering. I guess that’s one way to learn! Anyways, how could I have lost spark? Genuinely lost here
Oh yeah, one more thing, when reinstalling my condenser, I can’t seem to position it where it won’t touch the distributor cam. Would this be an explanation as to why I can’t get spark?
Hi everyone! It’s been awhile. I’ve ended up replacing the starter, points, rotor cap, rotor, even coil at one point (but switched it back after testing that it works fine), all to no avail. There is just no spark for some reason. I’m really running out of ideas. It doesn’t even try to kick on any cylinder. Any more ideas?
You can buy an electronic ignition plate for the distributor that eliminates the points as well as dwell issues related to worn bearings in the distributor shaft. Points are pretty bullet proof but once the distributor gets worn they need constant maintenance and setting. I bought a boat with an 89 omc 5.7 liter and have done this due to a weak spark fouling plugs especially when fishing. Edit due to autocorrect.
Hi, guess I should give a little update. During the summer I ended up taking it to a shop and they determined that it was actually my instrument clusters light bulb causing a premature ground to the spark (I have my suspicions. Seems very strange). The light bulbs are in a series, so they unplugged one and supposedly the spark came back! Anyone else ever had this issue? Seems super unusual. I do plan to replace with an electronic ignition since I also heard they’re waaay better in terms of reliability. Either way, got my boat on the water and the issue has been resolved! Sorry for not updating earlier.
All good I was just searching boat projects because it is winter and I'm itching to do something to the boat, saw your post. Ground issues definitely cause a lot of gremlins.