1969 55hp Johnson

[Julien 4788]

Hi,

I have a question regarding a 1969 55hp johnson.
We have one here we are restoring. Got spark, electric shift works but it will not fire even with gas sprayed in cylinders/carbs. We still have to check compression and spark when spark plugs are in the cylinder (might be the battery thats too weak for the amplifier when there is compression, the battery charger indicates less than 11 volts when cranking).

But one question we had is for the neutral safety switch on the breaker plate. Is it supposed to be grounding(aka engaged)? We saw it wasn't always grounding when depressed and we grounded the wire directly to the block for testing, is this correct? We are not sure what's the purpose of this switch any insight would be appreciated.

 

[racerone]

That switch prevents cranking with throttle too far open.-----Does spark jump a gap of at least 3/8" on a test device.----Test with the spark plugs in the head.

 

[440roadrunner]

Yes, how good is the spark? Condition of plugs? Compression will stop plugs from firing if they are denegrated, AKA contaminated insulators

I would get larger/ charged battery. Are you sure what you are spraying in is actually gas and IS IT fresh? Only other thing I can thing of is it possible the crank key is sheared

 

[Julien 4788]

Thanks for confirmation!

spark is strong blue real snappy. plugs are probably 20 years old but look ok, changing them would indeed be a good idea.
When we were testing we lost spark after a while hence i think the battery is probably the cause. I read somwhere that these amplifier systems needed a real good battery, the crank assist on the charger is probably not giving a true 12 volt to the amplifier. i doubt the compression is bad but need to test it properly

also can't get back to it before next week...

 

[racerone]

The flywheel key sheared on that motor has nothing to do with spark or timing.-----Compression should be 140 PSI + on that motor.-----If you put gas in the cylinders it should bark like a wild dog or roar like a lion.---The rotor key is in the right place ?

 

[Julien 4788]

The flywheel key sheared on that motor has nothing to do with spark or timing.-----Compression should be 140 PSI + on that motor.-----If you put gas in the cylinders it should bark like a wild dog or roar like a lion.---The rotor key is in the right place ?

humm that sounds like it. all we got was 2 backfires---- though it never seemed like it was sheared after pulling the flywheel a few times, we will have to check that.

 

[racerone]

???----The rotor has a key on it that must go in a notch on the crankshaft.-----Back firing indicates timing off or plug wires on the wrong plug.

 

[Julien 4788]

ok this may sound noobish but maybe we could have wired the coil backwards? Which post is the secondary circuit (that goes to the distribution cap) ??

 

[racerone]

The large post goes to the cap.----The smaller post gets the wire ( blue ? ) from amplifier.

 

[racerone]

So is that how you had it ??

 

[Julien 4788]

So is that how you had it ??

Yes,
i think you are right, the rotor (the black round thing with a notch under the distributor cap) must be in the wrong place. I will keep you updated when i get back to it