Good spark with new 12V ignition but will not start? Help!

[cdcarda]

My 72 kitty cat died on its maiden voyage this year. It lost spark again. My coil wire snapped off last year next to the coil and would leak the HV to the case. I tried JB-Weld and that cracked again so rather than spend over $100 on a new or used - impossible to get coil for the T5A engine I spent the $45 at Fleet farm on a 12V Tractor coil, ignition wires, and a motorcycle battery. I wired it all up with a fuse, On/Off switch, and a tether to kill it if necessary. I followed the posts of Eric form December 2003(listed Below) It has great spark now, the best that I have seen on this machine. Now I can't get it to start up. I look at the plug out of the machine, it sparks like mad. I put it in, and I have only had it pop once or twice. I thought maybe it had flooded. I let it dry out, but the same result, no go. Do I maybe have something else going on? I have heard about crank seals going out, but it still pulls pretty hard so I think the compression is good. Does this setup knock it out of time? Do I need to move the ignition plate a bit? Thanks for any help you can give. My 5 year old wants to ride it again really bad.

Chad


************OLD POSTS THAT I FOLLOWED*****************
Eric Guest Posted: Sat Dec 27, 2003 5:59 pm Post subject: CONVERT MAGNETO TO 12V COIL AND BATTERY Reply with quote
I bought a kitty cat for my 5 year old. It ran badly, but I thought all it needed was the carb cleaned. I didn't know that parts for the old Kawasaki engines are hard to come by. After replacing the crank seals and gaskets, the motor wouldn't run at all. It would fire, but spark was random. I figured it needed a coil, but the AC dealer said they couldn't get them.

My dad suggested doing what he did to his old John Deere tractor years ago: convert the magneto to a 12 volt system. I bought a coil, hooked it up to the engine with an auto battery and it started on the first pull!!! Now all I need to do is get a small 12 volt battery, mount it and the coil somewhere under the hood and hopefully it will run long enough between charges.

Here is what I did:
-cut the small wire from the magneto coil to the condensor to disable the magneto and isolate it from the 12 volt system
-put a fuse between the + post of the battery to the + post of the coil to protect the wires in case of a short
- the coil I bought doesn't need an external resistor, some do, make sure you get the type that doesn't need a resistor (unless you don't mind adding a resistor, too)
-connected the wire from the points to the - post of the coil
-connect a new spark plug wire from the coil to the spark plug

The points still are used, obviously to make sure the timing is right. The original coil could probably be removed. Before you hook things up, brush the hot wire to the + coil post to make sure there is just a little spark. If it violently sparks, like a welder, you have a short circuit. It's a good idea to put a fuse in to protect the wiring and points.

Hope this helps anyone who was considering buying another engine because they gave up on the old Kawasaki engine. If you have any suggestions please post them. The engine is mounted on my work bench and I quickly hooked everything up, and hope I have the coil polarity right. If not, let me know. I still have to get a small battery and mount everything under the hood. The key will be connected between the fuse and coil.

Thanks Dad, for the great suggestion.
Back to top

Eric Guest Posted: Wed Jan 14, 2004 3:02 am
Post subject: Reply with quote
Update on magneto conversion.

I bought the smallest 12 volt battery I could find, fabricated a shelf for it on the right side under the hood. It fit just right between the tunnel and side of the hood. I put a fuse between the + terminal and switch.

The coil was mounted below the starter recoil. If you can find a shorty coil it would fit better, but the standard size coil fit OK.

The switch is electrically backwards, though. To shut off a magneto you ground the coil. To shut off a 12 volt system you open up the circuit to the coil. Just make sure the switch is REALLY off, in this case it is left at the RUN position if you use the original switch. Might not be a bad idea to use a regular 12 volt switch that corresponds to the labels on the instrument panel.

My son drove it for at least an hour and I haven't charged the battery yet. I suspect it would run for days before needing a charge.

[cdcarda]

Today I cleaned out the carb and replaced the crank seals on the '72. I am still trying the electronic ignition as listed in the origional post. Plenty of spark but only a couple of pops. It floods out after little trying. What should I try now? I am at a loss. Any suggestions would be greatly appreciated. Thanks in advance.

[cdcarda]

I tested the compression and it is over 110 Psi. Is there anything else that I can try to get this old T5A motor going. I am almost ready to say "screw it" and drop on a Briggs or a Tecumseh to make it go. Thanks in advance for any help.

[Engineer]

Chad

Running 12VDC into the points and coil will give you a great spark. The only problem you’ll have is keeping points in it with that much voltage. Those automotive coils for cars use a resistive wire or ballast resistor to drop the voltage to 3-6VDC. I suggest you add a Chrysler ballast resistor in line to protect the points and you will still have plenty of spark.

With the voltage issue out of the way, we can concentrate on timing. With the spark plug out and lying on a grounded surface, pull the engine over slowly while watching the piston and the spark plug. Does it spark just before the piston is at the top of the cylinder? You may have a timing issue with way you have modified the ignition.

[AL]

Engineer is right about the ballast resistor and the points pitting real bad. However keep in mind that a ballast resistor has more than just the resistor. Lets not forget the whole idea behind the ballast resistor was to drop the voltage AFTER the engine is running. It still delivered 12 Volts to start the engine but dropped it down through the ballast resistor once the engine is running which demands a solenoid or switch of some sort to regulate when it needs 12 and when to drop it down. Being your using a 12 volt coil it's probably a good idea to use 12 volts to start it. I personally would use no ballast as several older bikes use a 12 volt system and points with no ballast unless your comfortable using a switch to regulate it being that a solenoid is out of the question since you have no spring ignition to do the job for you.