1975 Chrysler 75 HP Outboard Weird Spark Issue

[Fedboy2017]

Hi Guys,

Long story short I bought a boat with engine that had no spark. fixed the no spark. sort of. for what ever reason when cranking there is NO spark at all. when stop cranking it gives really strong spark. I don't understand what the hell is going on with that, I'm a 3rd year apprentice mechanic and never seen this issue before. Any advice would be highly appreciated.

Note: Compression all Cylinders 110PSI
Carbs are clean.
Starter works.
No corroded wiring anywhere
No corroded grounds
New Plugs
Replaced ignition CD unit as the old one was stuffed
Have removed thoroughly cleaned the Distributor cap points and rotor (did not remove rotor)

 

[racerone]

Starter may be drawing too much power.

 

[Fedboy2017]

Starter may be drawing too much power.

what can cause that?

 

[racerone]

Weak battery.----Load test required.---Bad starter.----Take it apart and do some testing on it.

 

[Fedboy2017]

Weak battery.----Load test required.---Bad starter.----Take it apart and do some testing on it.

I know its not the battery 100%. Tomorrow I'll take apart the starter and upload some photos. I've been sus on the starter as it has issues fully engaging and was planning on a tear down and deep clean depending on its condition

 

[racerone]

Is the battery big enough?---And have you had it load tested ?

 

[Fedboy2017]

Is the battery big enough?---And have you had it load tested ?

I know its not the battery because when its been low I've put my 3000AMP jump pack on it. its rated to jump up to 12 cylinder petrol and 8 cylinder diesel. it does the exact same thing. Unless you wanna try and tell me my jump pack isn't strong enough to start a 3 cylinder 2 stroke when it jump starts a Chevy Silverado 2500 Diesel without hesitation. I've also put my 760CCA 100AH battery on it as I thought it could have been a bad battery. same result

 

[Mc Tool]

I would be looking at the power supply to the ignition system , sounds like maybe the power is being cut to ignition when you turn the key to start . I would look at the ignition switch 1st, use a meter or test light to verify power to ign both when in the on position and the start position . I dunno about the wiring but Im sure there will be a wiring diagram out there somewhere.

 

[Fedboy2017]

I would be looking at the power supply to the ignition system , sounds like maybe the power is being cut to ignition when you turn the key to start . I would look at the ignition switch 1st, use a meter or test light to verify power to ign both when in the on position and the start position . I dunno about the wiring but Im sure there will be a wiring diagram out there somewhere.

yeah there's lots out there and easy to get ahold of for that. found something strange though. they added a wire to the start position in which it cranks. undoing that and using the factory harness it will not crank. I checked the safety switch and its functional.

with the added wire I get crank but no spark until you stop cranking
with the factory wire I get no crank lol. and can hear the starter solenoid click with the ignition key. think I might have to re-do the entire ignition key.

 

[Mc Tool]

yeah there's lots out there and easy to get ahold of for that. found something strange though. they added a wire to the start position in which it cranks. undoing that and using the factory harness it will not crank. I checked the safety switch and its functional.

with the added wire I get crank but no spark until you stop cranking
with the factory wire I get no crank lol. and can hear the starter solenoid click with the ignition key. think I might have to re-do the entire ignition key.

Yep , sounds like your in the right area . Is it possible that the kill switch is working when in start pos. Im thinking that the extra wire is probly there to fix another fault rather than buy a part so someone has been in there . Id be suspicious

 

[Fedboy2017]

Yep , sounds like your in the right area . Is it possible that the kill switch is working when in start pos. Im thinking that the extra wire is probly there to fix another fault rather than buy a part so someone has been in there . Id be suspicious

just people being lazy. its CDI box was 100% dead though and I have replaced that hence the spark.but also can't help but wonder if what they did was the cause of that or just because it wouldn't crank. I had a similar issue on my old Mercury and it was caused by a faulty tilt/kill safety switch. was thinking something along those lines for this same issue but haven't been able to find out much of anything relating to that kind of issue

 

[Fedboy2017]

lucky me. NOT.....everything engine side connected correctly. ignition switch side found 2 wires not connected, tapped and hidden. god I wish I knew who did this I'd tear em a new one for it. Wasn't the people I bought it from, they only told it needed a CDI box. clearly bullshit. why people can't just track down the actual issue instead of doing dodgy **** is beyond me. I'll post the outcome after rewiring the ignition correctly

 

[Fedboy2017]

What I found yesterday. Starter motor is the original to the motor, the starter's mounting bolts never been touched until yesterday, it doesn't look too bad however I'm going to replace it based on its age as well as the starter solenoid is activating intermittently. then Go from there