“Google” using starting fluid on a 2-cycle engine.

Is this motor using the original “pressure tank” setup?

I would suspect a fuel supply issue.

rhalbert10@outlook.com wrote:

This is my 1956 Johnson Javelin 30HP motor on my runabout.  Apologies in advance of the long post – I wanted to try and give as much of my experience as possible to “paint the picture”

• Started this season off solid – multiple rips to water, tuned my high throttle nicely and everything seemed to be running just fine.
• Opening Day here in Seattle in early May – out on boat waiting for others.  Stopped boat for a while, restarted fine.  Motor died while traveling slow.  Could not start the boat and eventually needed a tow to the boat ramp.
• Tested spark plugs – no spark on lower spark plug.
• Took flywheel off this weekend – replaced points and condensers.  Coils tested out fine with Ohm Meter so left in place.
• BUT!!!! The “key” on the flywheel stem was sheared in half!!  (this, *I think* explained some slippage I felt on the water occasionally and the fact that my top speed after tuning was 5-6 miles slower than usual)  Got a replacement key and then got flywheel reinstalled. I did find that a chard of the key was touching the stem and the magneto assembly and thought maybe there was some short…
• Tested magneto with spark plug testers and both were firing great so headed to the water today…
• Was not able to start the engine except by using starter into the carb.  Was able to get it started and idle for 5 minutes.  Cut engine, tried to restart and no bueno.  Tried more starter fluid, got some pops but never got it running again for any period of time.
• Headed home – tested spark plug /magneto and got a spark on both.  Then tested both spark plugs and got a spark on both of those as well.  Took flywheel off again to examine magneto.  One of the points connections was off-parallel so I replaced that one so that it had a very even gap (could this have been the issue?!!! – Does not feel like it…).  Set gaps to speck and put flywheel back on.
• The last thing I noticed was that after everything was installed. there was a little “play” of the magneto assembly if I put my fingers under the flywheel and lifted – just a little but did not remember ever feeling that before.

In the spirit of spark + fuel + oxygen, I feel the spark side of things is really good.  The other 2 I am way less confident on how to diagnose.  Any guidance from this esteemed group would be much appreciated.

Many thanks in advance.

Best,

Rich

Well I don’t know about an “esteemed group”!   Most of us struggle just like you.   We have all learned from doing.  Fuel, spark and compression and its gotta run!

dale

Like others have said, try removing the plugs, squirting some fuel/oil mix directly into the cylinders (do not use starting fluid), to see if the engine will fire briefly.

You mentioned a sheared flywheel key, that is not good.  Usually, the mating tapers get galled up when a flywheel key shears.  Be sure to properly torque the flywheel nut, you may need to lap the flywheel/crank tapers to get the proper fit.  But, if you have spark, then the flywheel key is not sheared now..