71 Evinrude 100hp ignition help.

J

justinth77

Recruit
Joined
Sep 25, 2004
Messages
1
hi everyone

i recently bought a 71 evinrude 100hp (100193a) very cheap. it has had a cheap aftermarket coil put on it and the amplifier is missing. it was running i was told, but the coil kept blowing. i'd say due to no amplifier.
can someone please explain to me what the amplifier actually does in detail, and can any one point me in the direction of a wiring diagram?

cheers
justin
 
R

R.Johnson

Rear Admiral
Joined
Sep 24, 2003
Messages
4,446
Re: 71 Evinrude 100hp ignition help.

I know longer have my service information, and I can't remember. Does that engine use points, or a sensor? If the engine has a sensor, it certainly won't run without a power pack. That engine has battery CD ignition, or it should. You will need a service manual to get anywhere. That engine could be very exspensive to get running. When you do get it running, you have the hydro- electric gearcase as a concern.
 
T

tacodads

Seaman Apprentice
Joined
Jul 12, 2009
Messages
41
Re: 71 Evinrude 100hp ignition help.

The amplifier steps up the 12 volts from the battery to 300 volts to store in the energy storage capacitor. When the points open they trigger the amplifier. this discharges the 300 volt energy from the storage capacitor to the coil where it is boosted to 25000 volts for the spark plugs. (I'm writing this straight from the repair manual)
So I'm thinking that without the amplifier, you don't have any stored energy for the coil. Coils good just no energy. You can usually get the amp at iboats, it's out of stock right now. you can also get it on the evinrude web site.
 
pitprice

pitprice

Cadet
Joined
Jan 20, 2010
Messages
23
Re: 71 Evinrude 100hp ignition help.

Hi i'm prettysure i have the same engine as you 1971 100hp Evinrude Starflite.

Our Amp recently blew and we had to get a new one shipped to NZ from the US. Shipping cost a bomb but luckly friends brother brought it over. We installed it last night and she was running great today sounded loads better as well. If they have none at iboats try the link below, amp worked perfectly and came with a new coil as well.

http://www.magemarinestore.com/mostampforom.html

A strong battery is recommended as the any kind of surges and drops in power can blow thw coil.

If want any help give me a shout with questions i don't know so much about boats but was in the same situation as you.

Cheers
 
F

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: 71 Evinrude 100hp ignition help.

justinth77 said:
hi everyone

i recently bought a 71 evinrude 100hp (100193a) very cheap. it has had a cheap aftermarket coil put on it and the amplifier is missing. it was running i was told, but the coil kept blowing. i'd say due to no amplifier.
can someone please explain to me what the amplifier actually does in detail, and can any one point me in the direction of a wiring diagram?

cheers
justin
Click to expand...

Sounds to me like one of the many attempts to put a car coil and condenser on it and doing away with the electronic ignition amplifier. Some have said they work, but not for long.

If the conversion has burned up the points, you might as well know they are no longer made and are $expensive if you can find any. Add the cost of an amplifier and whatever else they screwed up, and you will see why you got it cheap.
 
You must log in or register to reply here.
Top