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1956 super fastwin no start help please

O

Oldboatmotorneedshelp

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Motor will not fire
15 hp tiller, It will spit once if I spray starting fluid down the intake but that’s it
Pulls over very hard
Here’s what I have done to the motor so far:
Fresh non oxygenated gas mixed at 24:1
New champion JC6 plugs
New gasket for the pressure gas tank (used to leak)
At this point I don’t know what the next step is, I would think it would at least run for a second if it was a fuel issue so I’m guessing electrical but I’m no expert by any means. I’m considering taking in to the shop but I thought I’d post here and see if I’m overlooking something simple and obvious.
Any advice on the next steps?
Thanks
 
By switching plug wires do you mean reverse upper and lower? If so I tried that to no avail.
If you mean replace with new wires I do not have any to install at the moment.
I checked for any arc with the boot 1/4 inch away from the plug tip when pulling it over and I see nothing.
 

Here are 2 links, one is of the motor being pulled over with the boot removed to check for arc. Second is of it being pulled with a good amount of starting fluid, you can see it fires just for a split second then nothing.
 
If spark can not jump a gap of 1/4" you really do not have spark.----Just my opinion that will never change !----Remove flywheel / inspect and repair this simple magneto.----You must have strong spark to start this motor!
 
If it hasn't been started in a while, try squirting oil into the cylinders.
I know the fuel mix says 24:1, I mix mine at 32:1. It's just too much oil in my mind.
If you have a single line fuel tank you need the vent opened to run. I've never dealt with dual line system but yeah it would need to be pressurized.

There isn't much to wiring on these engines but there several things that might keep them from firing. Besides the possibility that one or both coils could be bad, the 7mm plug wires might also have connection issues due to deterioration. Check these when all else fails to work. The points need to be set @ .020in this is the only timing adjustment, don't get it wrong.

Then there is synchronization which adjusts spark advance to throttle position. This is an adjustment to the throttle linkage with the stator and its cam and cam follower. Buy the Book! For this reason, at least.

But the Big stopper is the condition of the black wires coming off the points. These wires constitute the kill switch. One and it doesn't matter which, goes to the cutout switch center terminal, which should be isolated (there should be no continuity to ground when the points are not connected,) except in a runaway condition, then connects to the kill switch. The other black wire goes to the other side of the kill switch, a momentary contact switch (push and hold to kill/pull safety line to kill.) The Idea is, ground the points the engine stops firing. If either point set is grounded that set of points will not fire. points are grounded when they are closed.

There are other safeties; throttle position must be slightly open (run position on throttle handle but not so far opened that the engine can be shifted into fwd/rev.) Older engines have mercury switches in throttle linkage. Engine must be upright not tilted. mercury switch in head connected to center of cutout or connected to starter solenoid ground in electric start models.
 
racerone said:
If spark can not jump a gap of 1/4" you really do not have spark.----Just my opinion that will never change !----Remove flywheel / inspect and repair this simple magneto.----You must have strong spark to start this motor!
Click to expand...
Magneto? Can you provide a link to where I can purchase one. I can search this site as well but it sounds like you have a good idea what I’m looking for
 
Remove the flywheel.---Use a puller with 3 (1/4-20NC ) bolts.----You will find 2 sets of points. 2 condensers ,and 2 coils.----Post picture of these items when flywheel is off.----An elegantly simple unit.----Lots of tutorials on U-tube on this item.
 
racerone said:
Remove the flywheel.---Use a puller with 3 (1/4-20NC ) bolts.----You will find 2 sets of points. 2 condensers ,and 2 coils.----Post picture of these items when flywheel is off.----An elegantly simple unit.----Lots of tutorials on U-tube on this item.
Click to expand...
Okay, I’ll need to buy the tool first.
This could be a few days before I get it removed.
Thanks
 
Oldboatmotorneedshelp said:
Magneto? Can you provide a link to where I can purchase one. I can search this site as well but it sounds like you have a good idea what I’m looking for
Click to expand...
The Magnets of the magneto are built into the flywheel. The points, condensers and coils are screwed to the Stator plate.
This system is THE MAGNETO

These parts usually don't fail.
Points will wear (transfer metal from one contact to the other,) if the condensers are (rarely) bad usually from heat.
Coils will fail if they get too hot. Look for cracks, burnt exposed wires. Any damage... Replace don't question.

The plug wires are screwed onto a small stud in the output of the coil through a grommet. insure contact.
The coils have two small wires one routed as a frame ground the other goes to the points along with the condenser and the black point wires.
The condenser wire and coil wire can if not routed carefully, rub on the Cam. This could be your problem.
The black point wires and the Plug wires are strapped to the bottom of the stator plate and can get friction wear from the stator turning. Which it does when you open the throttle. Any pinching or insulator damage is reason for concern replace the wire.

The points need to be set at .020 inches using a wire gage not a blade, measured when the set of points you are setting has its cam follower on the highest point of the cam which is part of the crankshaft.
The Coils need to be aligned with the machined surfaces on the stator plate before tightening.
The stator plate is removed by the Phillips head screws. Beware points clearance with cam on re-assembly.

I've never worked on anything older than 60'. I have done this with a 64' 18hp. While scale and part numbers change, the magneto on your 56' 15hp is the same as my current 64' 40hp, and the 18hp.

4 stator pics from 64' 40hp. note throttle limiting of stator plate with shifter linkage in Neutral, Reverse and WOT
 
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