1971 Evinrude 100hp - No spark?

[pitprice]

Hi I took my boat out this weekend and could not get her to start!!

She is turning over but never kicked in. I have done a bit of investigating and it looks like i am getting no power to the spark plugs. Does anyone have any suggestions on what the problem could be? I am new to boats and this is the first time in the couple of months of owning her that she hasn't started.

Also when i got her home after a few hours driving and all parked up she started slowly leaking oil from where the prop meets the housing? No much but enough to be concerned about i think. She has never done this before either!!!

Thanks for any help i've attached some old photos in case this helps anyone

 

[bktheking]

Re: 1971 Evindrude 100hp - No spark?

Re: 1971 Evindrude 100hp - No spark?

Does the motor have a kill or lanyard switch?

 

[F_R]

Re: 1971 Evindrude 100hp - No spark?

Re: 1971 Evindrude 100hp - No spark?

The stuff running out is the gas that went through the engine when you were cranking it and it didn't burn. So, it ran out the exhaust, picking up black carbon and crud from the exhaust pipe as it did.
No point in typing all this again. See http://forums.iboats.com/showthread.php?t=371137 Motors are similar.

 

[pitprice]

Re: 1971 Evindrude 100hp - No spark?

Re: 1971 Evindrude 100hp - No spark?

Does the motor have a kill or lanyard switch?

I'm almost certain it doesn't but i could be wrong! I've had a good look for one but can't see anything that looks like a kill switch to me.

Cheers

 

[pitprice]

Re: 1971 Evindrude 100hp - No spark?

Re: 1971 Evindrude 100hp - No spark?

The stuff running out is the gas that went through the engine when you were cranking it and it didn't burn. So, it ran out the exhaust, picking up black carbon and crud from the exhaust pipe as it did.
No point in typing all this again. See http://forums.iboats.com/showthread.php?t=371137 Motors are similar.

Few that looks like one less problem then, i've had a look at the link and will attempt to follow the first steps or so and see how i get on.

Cheers

 

[slim82]

Re: 1971 Evinrude 100hp - No spark?

I have this exact same motor. I lost all spark to my plugs over the summer. the ignition system on these motors is somewhat complicated. My problem was that i fried my amplifier box on back of motor. it would be the black box with red label made by motorola on you motor. do a search for trouble shooting omc amplifier or ignition box and perform these checks it can help determine the problem. the amplifier can be as expensive as 400.00 to replace. I shopped around on the internet and got mine for about 250.00 i installed myself with the shop manual handy boat fired right up and ran perfect all summer. also you might check point gap it should be .010" i had a point wear down and cause my box to short out also low battery voltage will fry these boxes.

 

[pitprice]

Re: 1971 Evindrude 100hp - No spark?

Re: 1971 Evindrude 100hp - No spark?

The stuff running out is the gas that went through the engine when you were cranking it and it didn't burn. So, it ran out the exhaust, picking up black carbon and crud from the exhaust pipe as it did.
No point in typing all this again. See http://forums.iboats.com/showthread.php?t=371137 Motors are similar.

I have followed the steps below and have no spark at the coil wire (distributer end) at any stage when the ignition key is turned or when the motor is cranking.

I do have 12v going into the amplifier on the red wire (it is actually purple for some reason) when the key is on.

If i am reading your previous posts correctly it is either my amplifier or coil that are shot? Correct?

Any suggestions on how i can narrow it down to one of these two parts?

Cheers

1. See if you have 12V on the red wire going to the amplifier when the ign key is on. If not, find out why. If you do have 12V, go to 2:

2: Disconnect coil wire from amplifier, then unbolt coil and unscrew the whole thing from the distributor cap. Remount coil and connect amplifier wire. Rig up a spark gap off the end of the wire that you took out of the distributor cap. Crank engine: if you have spark off the coil wire the amplifier, breaker points, and coil are OK. No spark, go to 3:

3. Disconnect the wire going from the amplifier to distributor. Turn on key and brush the wire from the amplifier lightly across a bare metal item on the block. Does that create sparks off the coil wire? If yes, the amplifier and coil are good and you have a problem with the breaker points. (They are in the distributor).

4. If you have found that you have spark off the coil in #3, you have a problem with the distributor cap or rotor.

Distributor cap, rotor and breaker points are under the flywheel. You need a puller to get it off and a torque wrench to tighten the nut to 100 ft/lbs when reinstalling. All that stuff has to be clean, clean, clean. Breaker points gap is .009 at widest opening. There is an anti-reverse spring in there, a loop of silver wire. It must be in good condition and lubricated where it rides on the crankshaft with a VERY thin bead of EP grease.

We all had to go to school to learn this stuff. You just got the 5 minute course.

 

[pitprice]

Re: 1971 Evinrude 100hp - No spark?

I have this exact same motor. I lost all spark to my plugs over the summer. the ignition system on these motors is somewhat complicated. My problem was that i fried my amplifier box on back of motor. it would be the black box with red label made by motorola on you motor. do a search for trouble shooting omc amplifier or ignition box and perform these checks it can help determine the problem. the amplifier can be as expensive as 400.00 to replace. I shopped around on the internet and got mine for about 250.00 i installed myself with the shop manual handy boat fired right up and ran perfect all summer. also you might check point gap it should be .010" i had a point wear down and cause my box to short out also low battery voltage will fry these boxes.

I have narrowed it down to the amplifer or the coil i just need to find out which one now, probably the most expensive i guess!!

I'm sorry but i have no idea how to check the point gap? Or even where it is?? Could you give me an idea please

 

[pitprice]

Re: 1971 Evinrude 100hp - No spark?

A friend suggested we test the resistance on the coil to identify if that was shot. I only have a cheap voltmeter so it wasn't too acurate but it looks like my coil is the problem.

I have read elsewhere that you can solder two wires on to the +/- of a 12v light bulb making it into a crude test light and use it to test the wire out of the amplifier (the one that goes to the coil) and an earth. While cranking the engine and looking closely i should get the bulb to glow, even a faint glow is a sign the amplifier is working.

Does this sound correct to anyone. I'm going to give it a go tonight.

From the photo below can anyone tell me what the grey wire does? Should it be attached to anything? The number 7 screw slot is empty and the plastic cover suggests it should have a grey wire attached. It has been this way since i've owened the boat and it has beeen working so i don't want to mess with it before i know what it does.

"If it aint broke don't fix it"

 

[86 century]

Re: 1971 Evinrude 100hp - No spark?

you need to pull the fly wheel to check the points. There is a converion to an auto coil that will cost you a lot less.

 

[slim82]

Re: 1971 Evinrude 100hp - No spark?

Your grey wire should be for a tachometer circuit some boats use it and some don't mine doesn't. if you have to relpace amplifier you need to know if u want one with a tach circuit it will be more expensive. also just a heads up if you have to replace the amplifier the new one will require a new coil be installed or it will void the amplifiers warranty. Mine came with a new coil along with the amplifier.

 

[txboatman]

Re: 1971 Evinrude 100hp - No spark?

hey, glad to see someone else has the same motor...... and the same problem i had. I ended uo having to change the coil and the black box you have on the back of the motor. I am pretty sure that was the amplifier. As soon as i had that changed it ran like a top, and still does 2 years later. Mine was caused by reverse polarity from someone hooking the battery up wrong. I spent hours and hours thinking it was in the spark or the distributor. dont waste your time, just replace. I think the amp was 250-300? I do have the maunal OEM original if you need anything out of it. I could make a copy and send? or email? Just wish some one could have helped me when i started..... Good luck

 

[pitprice]

Re: 1971 Evinrude 100hp - No spark?

Great to see someone else still has one of these motors as well, yeah its been real difficult finding out much about them. One its been running its been and awesome boat.

The new amp arrived today with a new coil as well which i didn't even order, was very pleased about that after reading the previous post. I had to order it from the US and get it delivered to New Zealand as there seems to be nothing over this side of the world about these motors. The amp was around $350USD but postage was $200+USD!!!!!! luckly a friends brother from the states was coming to visit and brought it with him in exchange for taking him whitewater rafting.

If you would be able to make a copy of the manual and send it to me that would be amazing. I have had no luck at all searching NZ or Australia for one and i'm gonna have to start looking at the points gap and battery to make sure i don't blow the new amp, not sure i wanna do that with out a manual.

Many thanks to all who have posted to help out. I'll let you know how i get on.

Cheers

 

[phipps]

Re: 1971 Evinrude 100hp - No spark?

I have a 71 60hp and it sounds like they have the same ignition system. I didn't have spark when I bought mine and the amp turned out to be bad.

I think CDI sells the amp and coil as a combo.

 

[keithnra]

Re: 1971 Evindrude 100hp - No spark?



I have followed the steps below and have no spark at the coil wire (distributer end) at any stage when the ignition key is turned or when the motor is cranking.

I do have 12v going into the amplifier on the red wire (it is actually purple for some reason) when the key is on.

If i am reading your previous posts correctly it is either my amplifier or coil that are shot? Correct?

Any suggestions on how i can narrow it down to one of these two parts?

Cheers

1. See if you have 12V on the red wire going to the amplifier when the ign key is on. If not, find out why. If you do have 12V, go to 2:

2: Disconnect coil wire from amplifier, then unbolt coil and unscrew the whole thing from the distributor cap. Remount coil and connect amplifier wire. Rig up a spark gap off the end of the wire that you took out of the distributor cap. Crank engine: if you have spark off the coil wire the amplifier, breaker points, and coil are OK. No spark, go to 3:

3. Disconnect the wire going from the amplifier to distributor. Turn on key and brush the wire from the amplifier lightly across a bare metal item on the block. Does that create sparks off the coil wire? If yes, the amplifier and coil are good and you have a problem with the breaker points. (They are in the distributor).

4. If you have found that you have spark off the coil in #3, you have a problem with the distributor cap or rotor.

Distributor cap, rotor and breaker points are under the flywheel. You need a puller to get it off and a torque wrench to tighten the nut to 100 ft/lbs when reinstalling. All that stuff has to be clean, clean, clean. Breaker points gap is .009 at widest opening. There is an anti-reverse spring in there, a loop of silver wire. It must be in good condition and lubricated where it rides on the crankshaft with a VERY thin bead of EP grease.

We all had to go to school to learn this stuff. You just got the 5 minute course.

good stuff here

 

[F_R]

There was a neon tester back in the day that could detect amplifier output to the coil, but it is long ago obsolete. You can use a modern DVA tester if you have one and know what you are doing. It can also be done with a small light bulb, but I don't remember the details.

If I am not mistaken, the mfr of new amplifiers says to replace the coil at the same time anyway.

 

[GA_Boater]

8 years old and closed.