Chrysler 75hp '76 Suddenly Stopped

[shansta]

Hi all,

Was on my way out for a fish today and after a few kms my boat suddenly stopped, ended up getting a tow back home.

While waiting for a tow, i tried starting the motor several times, the only time i could get it to start was if I sprayed a fair bit of carbi spray into the carbs, but then it would die. I checked my fuel lines as I thought it was not getting fuel, but when I got home I took of the fuel filter attached to the motor and it was clean and seemed to be receiving fuel from the bubble/line fine.

I took out the spark plugs and they look pretty black, wet and smell like petrol. I am starting to think it may be a problem with the fuel not sparking correctly. I am not sure if the plugs are sparking and do not know how to test myself. So, instead I have taken a few pics of the plugs and was hoping someone could tell me if they look like they are no good, as I am hoping the is the cause of the problem. My motor is a '76 75hp Chrysler.

88162

Thanks,
Shannon

[Gon Fishun]

It sounds more like your fuel pump is not working.
If your not into things mechanical I would suggest you seek out a mechanic or a mate that is.
Cheers

[finga]

Just plug a plug back in (without screwing it into the head) and earth out the spark plug at the bit where the spanner goes and wind the motor over as if you were trying to start the old bugger.
You'll see spark if it's there.

Stage two after knowing if the spark is there or not.

[tunaticer]

Sounds to me like this may be an ignition wiring problem. From memory these motors had one coil per cylinder so it would be unlikely to cut out electrically from that source, more likely it is the ignition feed to or from the key. Your plugs are wet so most likely it is not fuel related. That style of surface gap plug very rarely fails regardless of age, mine are still running strong after 18 yrs.

[shansta]

Sounds to me like this may be an ignition wiring problem. From memory these motors had one coil per cylinder so it would be unlikely to cut out electrically from that source, more likely it is the ignition feed to or from the key. Your plugs are wet so most likely it is not fuel related. That style of surface gap plug very rarely fails regardless of age, mine are still running strong after 18 yrs.

How would the ignition feed cause the motor not to start? The engine still turns over when i turn the key. If it was an ignition problem wouldn't it not turn at all?

[Gon Fishun]

Sounds to me like this may be an ignition wiring problem. From memory these motors had one coil per cylinder so it would be unlikely to cut out electrically from that source, more likely it is the ignition feed to or from the key. Your plugs are wet so most likely it is not fuel related. That style of surface gap plug very rarely fails regardless of age, mine are still running strong after 18 yrs.

Hey TT. I have a 75, on my sons boat now. It has the magnapower . Not sure , will have to check the manual and the motor but I think in the mid 70's they changed from point ign to CDI. ???????
Shansta . Do you know what type it is.

[finga]

It could well be what Jack suggested. A positive feed goes to the ignition circuit and another positive feed makes the start solenoid work.
It seems blue is generally causing the ignition to go all sparky and yellow is generally causing the Rrrrr Rrrrrrrr Rrrrrrr Vrooom to happen so I'd be tracing the blue wire through to start with and testing everything in it's path.


A single crook earthing point can cause that problem too.
Has your motor got the distributor?
Do you know which ignition system it has?
If not then look here and decide which system you have.
http://www.maxrules.com/fixforcewiring.html

I had a quick look at the diagrams and it could be anything causing the thing not to fire. Anything from a crook connection to a crook capacitor to a crook interlock.
As near all of them have a CD unit I reckon the problem may come back to there.

[finga]

Oh....if you cannot decide which ignition system you have I would be looking for another motor as more then likely no mechanic will look at it.
I know of a really good low hour 2 stroke 75HP Marineer laying about and I reckon you could own it for $2,000.
He just upgraded to a 90.

[Steeler]

Hey Finga, what year is the 75hp grey one ?.

[finga]

Buggered if I know. 90's or so I'd reckon off the top of my noggin.
The bloody boat sat in the shed for about 12 years and used a couple times a year that I know of and he went fishing around Gove late last year so he had it checked for everything and near everything that could break down was changed.
Not a bad motor really and was thinking about buying it to shove on a E-bay boat and flog the package off. But I have waaaaaay too much on my plate at the moment.

[Steeler]

Clam style cowl and integral pwr t/t not a wrap around style like your tower of power

If thats the model with the oil bottle just forward of the starter on the strbd side and not the auto blend remote bottle type that is a dead set good buy.

[finga]

Yep. Definitely clam shell cowl and pretty sure of the oil bottle in the motor.
Vast majority of work has been in freshwater as well.

[shansta]

It could well be what Jack suggested. A positive feed goes to the ignition circuit and another positive feed makes the start solenoid work.
It seems blue is generally causing the ignition to go all sparky and yellow is generally causing the Rrrrr Rrrrrrrr Rrrrrrr Vrooom to happen so I'd be tracing the blue wire through to start with and testing everything in it's path.


A single crook earthing point can cause that problem too.
Has your motor got the distributor?
Do you know which ignition system it has?
If not then look here and decide which system you have.
http://www.maxrules.com/fixforcewiring.html

I had a quick look at the diagrams and it could be anything causing the thing not to fire. Anything from a crook connection to a crook capacitor to a crook interlock.
As near all of them have a CD unit I reckon the problem may come back to there.


Im not sure exactly which ignition system it has but I am thinking either the magnapower delta or motorola with alternator..

I do have a mechanic I am taking it to tomorrow.

Here is a pic I took anyway
88174

[LittleSkipper]

Im not sure exactly which ignition system it has but I am thinking either the magnapower delta or motorola with alternator..

I do have a mechanic I am taking it to tomorrow.

Here is a pic I took anyway
88174


Looking at that picture of your motor under the cowling certainly would have some history about it?

[shansta]

I took it to the mechanic, after i broke the ignition switch and he fixed the switch and said compression was 145 on all and the reason it stopped was because only 1 cylinder was getting spark.

I just got it home and well it starts but doesnt want to run for longer than 10-20 seconds. When i first started it up it did a huge backfire. So I dont know where to go from here...

Here is a video I took just minutes ago.. http://www.youtube.com/watch?v=RdDiQunV_Wk

Cheers

[MudRiverDan]

Its probably broken I am sure you can pay a marine mechanic to fix it.

Thanks

[tunaticer]

Now it is firing like that I think you have upset the troll living beneath that cowling and its now got a fuel supply problem.

Do you like rowing??

Personally I would not be trying to fix it......

[shansta]

Its probably broken I am sure you can pay a marine mechanic to fix it.

Thanks

I thought I did when I paid him $200 today :/

[Gon Fishun]

It could a fuel supply problem. The motor has three carbies and there is a fuel pump where the fuel line from the tank joins on. I think you said you had fuel up to here, but is it pumping out to the 3 carbies. If the pressure is weak, you may only be getting enough fuel to 1 or 2 carbies and it runs rough like it does in the video. There is a slotted screw on the side of the pump which has a screen behind that, check and clean that first then check if fuel is pumping from the outlet. On the carbies, I think they have a hex head screw underneath holding the bowl on . Loosen these 1 at a time and see if fuel or water drips out. If you need a manual I have 1 on disc that I could probably email to you if you require it. It's one of those copied ones from ebay.
Cheers.