Condensor 30L

"After I adjusted the valves t

"After I adjusted the valves this weekend, took the 3.0L (1987) out for a test run. After ten minutes it died. No spark. Still no spark the next day when I turned it over while on the trailer. Replaced coil with a new one. Still no spark. Replaced condensor with an old one (none available at parts store). Got spark. The condensor that went bad was new in June. Only about one hour on it. Is there an underlying problem(s) that caused the condensor to go bad?"

"Jim
Although you expect much

"Jim
Although you expect much greater life than that, they are typical of ignition components they can last 20 years or 20 minutes.
I would be checking you have the right coil on your engine, does the ignition system use an external balast resistor ? Check your voltage at the + terminal on the coil with the ignition on,
if you have 12v or better you should have a coil with an inbuilt resistor fitted. If the coil fitted is not an internal resistor type and you are getting 12v at that + terminal you need to install a resistor in the circut.
Cheers
Peter C"

"Condensers are most notorius

"Condensers are most notorius being bad, brand new, right out of the box. Back in the days when all cars had them, if it misfired shortly after an electrical tune up, mechanics would throw another one in without giving it a second thought.

Heat can bring on symtoms in a coil or condenser and so would account for the intermittant behavior

There are two types of coils. Those that require external ballast resistance and those that do not. When replacing coils be sure to get the correct one. Coils are rarely a problem and typically last many years."

"The coil that was on the engi

"The coil that was on the engine says it needs an external resister. Likewise, coil that I bought at NAPA alledgedly for this engine says it needs an external resister. I checked the voltage at the positive terminal last night with the engine running it was 11+ volts.

Mechanic at local marina said he thought voltage with engine running should be around eight volts but he wasn't sure. (He seemed to be more familar with OMC products.) He suggested a new wire from alternator to coil. Mercruiser has a part for the retrofit. Does this sound right?"

Jim: The mechanic was right.

Jim: The mechanic was right.

If you have an electric choke there is a purple resistance wire running from the choke to the coil. The voltage at the choke is 12 VDC and the voltage should drop over the purple resistance wire to 8 VDC. You can install a new resistance wire if you can find it. I would replace the resistance wire with a standard 16 ga. wire and add the external ballast resistor between the new wire and the coil.

I wonder if the last coil was

I wonder if the last coil was selected in error and it should have been one that does not need external ballast.

"Jim
You need that external r

"Jim
You need that external resistor for your coil but you also need 12+ volts at the input side of the resistor not 11+.

Did you check the voltage with a digital meter ?

Guys suggestion about the fitting of an external ceramic ballast resistor instead of a resistance wire is the best way for my money, but make sure when you fit it, with the ignition in the on position, that you have a good 12+ volt supply to it, otherwise your ignition voltage at the coil will be to low and that will give you problems as well.

On my boat, I actually run relays on the ignition system just before the balast resistors, I use what would normaly be the 12v feed to the resistors to activate the relays and then bring the supply power to the resistors through the relays via fairly large wiring straight from the large B+ terminals on the starter solenoids, on the starter motors.
This ensures I always get a very good battery voltage supply direct to the resistors when the ignition is on and it improves the starting and reliability of the ignition system out of sight.

Cheers
Peter C"

Peter:

Great idea. What g

Peter:

Great idea. What gauge wire are you using? What is the amp rating on the relays? I am thinking about putting a sealed 40 amp box relay on my choke power supply so I can turn it off after the engine warms up which should give the choke heater longer life. What do you think?

"Peter:
I checked the voltage

"Peter:
I checked the voltage at the plus side of the coil with the engine running with a digital volt meter.

If I am understanding correctly, I should have 12v on the purple wire at the choke and then a lesser voltage on the purple wire at the coil.

I did purchase a resistance wire. It is Quicksilver part number 84-94227A2. I am to splice it into the purple wire coming out of the alternator and then connect it to the + side of the coil.

Where do I get a ceramic resistor? What do I ask for?"

"Guy
I used 4mm tinned wire r

"Guy
I used 4mm tinned wire rated at 15amp and the relays were rated at 15amp as well.
As far as your choke go's though, if you cut the power to the heater, the bi metal spring will start to cool off and recurl causing your choke to start coming on again so I think you are stuck with that one.

Jim
If you are going to use the resistance wire that will do the job for you but if you wanted to use the ballast resistor you can pick one up from any spare parts shop.
Just ask for a ballast resistor with bracket and mount it on your coil bracket, run the + ignition wire to one side of the resistor and then a short wire back to the + side of the coil.
You sould have 12v ignition supply to one side of the resistor and between 7.5 to 8 volts out of the resistor to the coil +.
Hope that helps

Cheers
Peter C"

Jim:

Just in case you are

Jim:

Just in case you are not clear on the resistance wire installation; if you have an electric choke there is a purple resistance wire running from the choke to the coil. You can install a new resistance wire in its place.

Peter:

Are you telling me

Peter:

Are you telling me that the heat radiating from the intake manifold and heads is insufficient to keep the choke coil in the open position? I'll take my new laser temp gun and see what the temp. is under the carb in several places while under way.

"Guy
I think it may not be en

"Guy
I think it may not be enough but the easiest way to confirm it of course is to just run your engine up to operating temp when the choke is wide open and dissconect the power supply to the heater and see what happens.
It will rather stay off or the choke will slowly start to close. Give it a go and see what happens, if it stays off you are in business, then you could just set up a timer circute to cut off the power after the ignition has been on for a pre determined period of time, or you could use a thermal switch to shut off the power at a set temp.
Wether it stays off or not will probably have a lot to do with your engine bay temp and that will have a lot to do with your blower and venting arangements.
Anyway see how you go and let us know.

Cheers
Peter C"

thanks Peter

thanks Peter