Force 50hp cylinder 1 no Spark

[Paulg443]

Hell all, I have a force 50hp ( Model : 507x6a )
The engine has good compression on both cylinders
and will start but runs only on cylinder 2.
I have swapped out the plugs and it makes no difference.
Any help would be appreciated.

 

[The Force power]

:welcome:

https://www.outboardignition.com/page6.asp

 

[jerryjerry05]

Your motor has a points ignition.
Most likely culprit is the points.
2nd guess? the coil has failed?

1st swap the coils/leads and see if the spark follows the move,
that shows if the coil is bad???
2nd: remove the flywheel and file the points, then retest spark.

Outboard Ignition doesn't cover the points system very good.
They did say:
Low voltage symptoms are weak fire or erratic firing of cylinders. Maintenance free batteries are NOT recommended for this application.

 

[chris.olson]

2nd: remove the flywheel and file the points, then retest spark.

While you're doing that I would suggest setting the point gap to .015 too. There is a mark on the cam that you line up with the rub block on the points to set them. Make 100% certain that both sets of points are adjusted identical. Because changing the point gap changes the ignition timing. So re-check the ignition timing after messing with the points.

When you do this there's a felt on each set of points held in contact with the cam by a fork-type clip. Pull that out and put a small amount of light grease on the felt, put it back in and make sure it contacts the cam. This what keeps the rub blocks lubed so they don't wear out.

There's also a little "trick" to getting the flywheel off. Put your three-screw puller on it and tighten it up as tight as you can by hand. Then use a small prybar to put a little pressure on one edge of the flywheel. It don't take a lot - don't break it. While you're putting pressure on there rap on the puller screw head with a hammer and it will pop free.

When it put it back together note the marks on the emergency rope start disc and flywheel. Those have to be lined up or it will shake like hell from being out of balance.

95% of the time, the points not opening because the rub blocks have worn is the cause of misfiring, lower power, or a cylinder that won't fire at all on these.

 

[jerryjerry05]

If you just run a file or piece of sandpaper on the points?
It won't change the timing, that just cleans the bit of carbon off the edges.
But do lube the wicks on the points.

 

[chris.olson]

If you just run a file or piece of sandpaper on the points?
It won't change the timing, that just cleans the bit of carbon off the edges.
But do lube the wicks on the points.

Not a bad idea to clean the points, but definitely check the gap too. Each .0012" of point gap changes the timing by 1 degree. Points that have had the rub blocks wear so the gap is only .009, for instance, you will find the timing retarded by 5 degrees, which is quite a bit. The Chryslers are cross-scavenged so he factory timing spec is 32 BTDC and many marinas that still service them retard them to 29 to prevent pinging to cope with today's ethanol-blended fuels. The proper thing to do is increase the main jet to 088 for ethanol-blended fuel and leave the timing at 32. But many mechanics don't do that and detune it instead. So you end up with an equivalent of a 40 instead of a 50, and if the point rub blocks are worn and retarded it further yet, you only got a 35.

Take a look at the timing rod and see how many threads you got left on it. If it has been adjusted to end of its threads you will find the points aren't opening far enough. Which increases the dwell, makes the coils run hot because the magnetic field in the coil primary does not fully collapse, and will eventually take out a coil. You'll end up with an open primary winding in the coil. Very important to make sure the point dwell is 29-31 deg on both sets after a tuneup to prevent coil failures. If you don't have a dwell meter then set them to .015 and be very meticulous in setting them both the same.