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point set,powerpack,ignition help

Ofak530

New member
I have a 1986 8HP 2-stroke Johnson outboard (pull start)

i am having issues getting both cylinders to fire, so far i have determined that i get spark from both coils. I can get one cylinder to fire(bottom cylinder) and idle with no problem, i even switched the coil wires around to see if i can get the (top cylinder) to fire (thinking the first coils spark was stronger) but then i cant get either to fire.

I am about to pull my hair out at this point, is it possible that im getting spark but the voltage is not strong enough? Ive read that in the manual and it said it might be the magneto. Is there a way with an ohm/voltage meter to measure the voltage from the coils? and what should the voltage be? i was told 1.5 volts

Is it possible that the point sets aren't adjusted and the spark plugs are firing at the wrong time?
What exactly does the CDI powerpack do?
What does the magneto do exactly?
Is there a way with an ohm/voltage meter to measure the magneto from the harness?

please help!
 
1.5 Volts from the coils?? Don't listen to whoever told you that. It should be in the tens of thousands of volts. Way out of a multimeters' capacity to measure. You measure it by checking to see if it will produce a spark. At least 1/2" spark.
 
1.5 volts is what is emitted from the timer base sensor coils (triggers) to fire the SCL (electronic switches) within the powerpack.

The timing sensor coil is what controls what coil will fire thru the powerpack, functioning via positive/reverse polarity of the flywheel magnets... Keeping it simple, that means if the timing sensor fires one coil it's capable of firing the other one. Yours is okay, no need to bother testing that component.
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Using a spark tester, available at any auto parts store... OR... using a #2 philips screwdriver tip stuck into the spring connector inside the spark plug boot, then holding that screwdriver shank 7/16" (approx) away from the block... you can do a pretty fair test of the ignition spark.
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Remove the spark plugs so as to be able to obtain the fastest rpm when testing.
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1 - You know the bottom coil fires and has spark but test it anyhow to get the hang of what the spark looks like when it jumps that 7/16" or so gap.

2 - Now the orange wire that leads from the powerpack to the bottom coil... remove it from the bottom coil and connect it to the top coil temporarily. Test the top coil now to see if the spark will jump that 7/16" gap. Does it?

If the top coil now has spark... BUT... it does not have spark when the proper orange coil wire is attached, the usual cause is a faulty powerpack.

But... if the top coil still does not have spark, then the coil is faulty.

Let us know what you find... be precise so that there is no chance we might misunderstand your answers.
 
Well I did a ohm test on the charge coil and it failed the test per the manual, it was supposed to be 575 +/- 50 ohms, it was 0.575kohms!

So I was getting spark but weak. I tested both coils and the sensor coil, and they passed the ohm test per manual.

Question: Which is the number 1 coil, and which is the number 2 coil?

Is the number 1 coil the one on top?

I need to put these wires back from the powerpack and I want to be sure. Thanks for your time.
 
There is just ONE charge coil under the flywheel and it is used to fire BOTH cylinders.-----So if it fires properly on one cylinder then why would it be at fault for the other cylinder ???
 
Well I did a ohm test on the charge coil and it failed the test per the manual, it was supposed to be 575 +/- 50 ohms, it was 0.575kohms!

So I was getting spark but weak. I tested both coils and the sensor coil, and they passed the ohm test per manual.

Question: Which is the number 1 coil, and which is the number 2 coil?

Is the number 1 coil the one on top?

I need to put these wires back from the powerpack and I want to be sure. Thanks for your time.

Um...isn't 575 Ohms same as 0.575 K-Ohms?
 
Do the test as I stated via post/reply #5.

Joe i have done that test, i have spark from both starter coils, and the sparks look the same.

So i have spark (both coils), good compression from both cylinders, and the carb is rebuilt, and yet i can only get one cylinder to fire and idle.


I was told today that it could be a reed sticking in that cylinder that is not firing. Before i go through all the work of taking the carb off, and getting to the intake reeds, is there a test to find out if its the reeds? If i spray starter fluid right behind the plug of the non responsive cylinder to see if it will pop would that determine the reed might be the problem?
 
(1986 8hp Johnson)
In your original post #1, we were led to believe by your explanation that one coil, for some reason, was not firing (had no spark). However, here in post #6, we see that you do have spark and compression... and a better explanation.

Use a bit of pre-mix fuel/oil in place of starter fluid for the test you mention as yes, that will tell you that the cylinder will fire if it has fuel.

As it stands here with your post #6.... either a leaf valve is stuck open or broken... OR... the carburetor is fouled,or the adjustable needle valve is set too lean (that needle valve, if adjusted too far in, will knock out one cylinder).
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(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
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I took the reed plate off to see if there was any damage to them.

View attachment 21060 I am having trouble getting the top cylinder to fire properly and idle (have spark) I can get it to pop but thats it. My question is, is the right side of these reeds the top cylinder (because it sits higher than the left?) If so that makes sense, the pictures below will explain.



View attachment 21061 Here are the reeds on the right side, as you can see there is damage to them. Could these little chunks be causing a lack of a seal thus not letting the proper pressure of air/fuel in that cylinder? How picky is the function of these reeds? The left side reeds look fine but i will be replacing all reeds since i have it apart.


Can i use gun solvent to clean the areas where the reed fingers sit? The manual says solvent, what do you recommend?
 
Your attachments come across as "Invalid Attachments".

The reeds, leaf valves are either perfect or they are not. Little chunks??.... any damage to those leaf valves would need to be done by something internal coming loose and tearing into them.
 
The reeds are chipped / defective.----Rarely seen on these small motors.----Possibly running above recommended maximum RPM.----Install all new reeds on this motor.
 
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