still no spark in lower cylinder

[scup27]

I have a 1965 40hp johnson super seahorse outboard. there was no spark in the lower cylinder so i took the flywheel off and tested everything. the condensors had the same resistance, the coils had nearly the same resistance. so it seems that the stator assembly is fine. the points are gapped properly at .020". the spark plug wires look fine but i havent had a chance to test their resistance. Anyone have anything similar happen to them??

 

[Joe Reeves]

Re: still no spark in lower cylinder

Switch the coils to see if the problem follows the coil.

 

[scup27]

Re: still no spark in lower cylinder

I changed the coils and the coil is not the problem. i changed the spark plug wire, swapped out the condensor with another one from an older unit and still no spark. Im getting a brand new condensor today but i cant figure out why there is still no spark. the points are gapped at .020''.

 

[tx1961whaler]

Re: still no spark in lower cylinder

Dsconnect the two black kill wires that come out from under the armature plate and see what happens.

 

[Joe Reeves]

Re: still no spark in lower cylinder

(Point Setting Of Magneto Models)
(J. Reeves)

Set the points as follows. Have the flywheel key aligned with the fiber rubber portion of the ignition points. Adjust the gap so that a .020 gauge will pass thru but a .022 will not. Should there be any question of the points being dirty (touching the contact with your finger would cause them to be dirty), clean them with a small brush and acetone or lacquer thinner.

NOTE: Should the operating cam have a small portion on it with the word "SET" imprinted, align this portion with the fiber rubbing portion instead of the flywheel key.

(Magneto Armature Plate)
(J. Reeves)

If the armature plate has a a loose fitting, wobbling motion (the plate that the points, coils etc are attached to), it is usually caused by a slightly worn support ring. This allows the point setting to change erratically as the armature plate turns.

The cure is to remove the armature plate so that the support which is attached to the powerhead with 4 screws is visible. Then, with a screwdriver and hammer, or some tool of your choosing, and looking straight down at the support ring, make an indentation at what would be called the 12, 3, 6, and 9 O'clock positions. Install the armature plate and check for a smooth turning wobble free movement.

You may need to do that procedure a few times to obtain the proper fit (not too tight, not too loose), but it's worth the effort.

Use a small amount of anti corrosive grease between the aluminum ring and the brass support plate and also on the brass bushing of the armature plate when all is well.

 

[F_R]

Re: still no spark in lower cylinder

You may not have one, but a multimeter (ohmmeter) that can distinguish resistances of less than one ohm is an invaluable tool for troubleshooting things like this. But if it can't tell the difference between zero and an ohm, it will be of limited use.

Check the resistance between the points and armature plate (wires still connected). It should be zero when the points are closed and about an ohm when open. If it won't zero, the points are not making good contact. If it won't vary between zero and the ohm, something is shorted or open.

 

[glassmaster68]

Re: still no spark in lower cylinder

disconnect the black wire connected to the no. 2 cyl point set thats not firing,the black one that runs out through the bottom of armature plate,there should be one to each point set,,only have the coil and cond connected to no.2 cyl point set,,,,if it fires without that wire connected then it is one of your cutout switches,,follow your black wire to the culprit

 

[scup27]

Re: still no spark in lower cylinder

i have both ground lines disconnected from the block, ill have to check the points with the resistance, but i did clean them with some dielectric cleaner.