Still Stalling

[Wilburt King Jr.]

Hello I have been dealing with a stalling problem since last season. At this point I have narrowed the problem to ignition troubles.

I have: changed points, condenser, plugs, wires, dist. Cap, resistance wire.

During my previous posts these were some of the suggested replies in addition to fuel issues. Therefore I completely went over the fuel system, filters, tank p/u tubes, water in the gas, proper tank venting, fuel pressure etc even ran using auxiliary tanks – no change in performance. Recently, I double checked the for proper timing using a light, noticed the spark was sort of inconsistent this lead me to my concerns about my ignition system.

Currently I am not getting a spark from the ignition coil (it’s very hot). I would just change the coil but I’ve done that before while it was in “stall mode” with absolutely no better result i.e. the engine would start but once in gear it would cut off. So now my concern is why are the coils burning out? Am I using the proper coils for this engine…I did purchase them from a marine supplier. In addition, if this is a 12v coil which needs an external resistance wire, then why when the resistance wire is cold it allows 12v to the coil + terminal? These 12v are in addition to the 12 coming from the slave solenoid at start up/cranking… do you need both voltages for start up with a 12v coil? Once the motor has started the resistance wire reduces the voltage going to the + side of the coil to 6 volts the boat will run for apprx. 30 minutes and then shut down until cool off period ends. I think I’m burning out coils, but I don’t know why! HELP PLEASE!

[David]

As I understand the coil will get 12 volts during crank the reduce voltage in run mode. Have you checked the shift interupt switch? This switch cuts voltage when shifting from neutral to forward or reverse, essentially stalling the engine for a moment in order to ease stress on the gearcase. If your stalling occurs during shifts, I would look there first. On another note I would strongly suggest converting to a pointless ignition system. It is a very simple conversion and much more reliable and maintenance free than points.

[Wilburt King Jr.]

Hello dave, that would be my concern, but I had the outdrive serviced last year which included replacing the shift cable. That procedure included adjusting the shift interuptor switch. In addition my stalling also occurs at full throttle after approx. 30 min. of drive time.

I do plan to convert to pointless ignition system as soon as I figure out this coil problem or ignition problem. The last time I ran the boat (30 min.) it cut off and would not restart, I checked for a arc on the primary wire and found no spark/arc going into the distributor. Therfore I fear that I'm burning out these coils.

Thanx
Wil

[David]

I would run the engine until it stalls and won't restart, then run 12 volts to the coil via jumper wire and see if it will start then.

[Wilburt King Jr.]

Thanks dave, that sounds like a good plan, I'll let you know the results.


Wil

[Wilburt King Jr.]

Okay I changed both the coil and the points to a Pertronix II system. She started right up, ran good but overheated in fifteen minutes of run time… this is new. Cut off the engine, allowed to cool. Restarted - again ran good unless I tried to accelerate which would cause the carburetor to back fire and again much like the overheating this was new to my engine i.e. only started after the ignition change. But on the brighter side the engine ran continuously for over an hour smoothly unless I attempted to rapidly accelerate. Do I need to reset my timing? If so, what degree? Do I need to readjust the carburetor idle mixture? My instructions with the electronic point system did not mention any of these symptoms. In addition all this happened on muffs in the back yard!

[David]

Yes, I would adjust timing. I would guess your initial timing should be about 15 degrees but you should check total advance and set it about 36 degrees. I doubt this has anything to do with overheating. It sounds like the acceleration problem is in the carburation. Set you timing, make sure the engine is at operating temperature then try accelerating. If it still acts up, especially since you are running on muffs and not under true load, then I think you need carb work.

[Lars Ekman]

Following your discussion about timing problem, what kind of engine do you have? On my 350 mercrusier with carb. it should be 8 degrades before TDC. timing @ 800 rpm with the pre-timing blocked. I think its 10 degrades before TDC with a fuel injection.
Greetings from Stockholm

[Wilburt King Jr.]

Thanks fella's reset the timing to original specs - 10*, and she's running flawessly of course still on muffs. I will launch this weekend and let you know if all goes well.

Wil

[Wilburt King Jr.]

I couldn't wait till the weekend,took off work thursday to lauch the boat. The boat performed great for over two hours before the crackle of thunder rushed us back to the launch. Stalling problem resolved...Thanks all!

[Chris]

It sounds like there is a ground somewhere in the ignition system. I solved a similar problem by simply going to an HEI ignition. It is a very simple change and is infinitely more reliable. Check out Performance Distributors Inc. www.performancedistributors.com/marinedui.htm
They have Marine units. I have been running mine for a number of years and it is rock solid.

Chris