Model hit or miss ignition fail

[dkwflight]

Hi
THis old brass engine has run. It was given to me to clean up and make run.
So far it has a buzz box like a model A.
The box is supplied with about 15 volts AC from a transformer,
I get no action. the vibrating point plate doesn't

 

[Gordon]

I don't think that the old buzz coil will operate on AC. It was designed to run on DC.

 

[dkwflight]

Hi
I am sure you are right, in theory. This engine has run for many years as is.
I am in the process of tracing a wire fault or loose connection.
I show 15+ volts through the wire connections to a point.
The wire uses the motor castings as part of the circuit.
Dennis

 

[Gordon]

I am not too familiar with the old buzz coil but my understanding is that it creates a buzz or false AC by make and break of the DC.

 

[dkwflight]

That is my understanding. THe building magnetism builds and pulls the metal leaf that carries the points. The points break as the leaf is pulled

 

[dkwflight]

THe transformer failed. As soon as I hook a 12 volt battery to the buzz box it starts.
Dennis

 

[dkwflight]

I just washed the old oil off with a solvent sprayer loaded with ethanol.
I did not want to disturb the nice old paint.
Dennis

 

[Steamchick]

I wash things in diesel fuel. It leaves the lightest oil film afterwards that helps resist rust. And is the lightest oil in my workshop for oiling delicate stuff. Then I re-oil the engine at oilers, bores, etc. But DON'T BREATH THE FUMES! Wear a mask when spraying. Wash well afterwards. You don't want to develop dermatitis or worse.
The dirty fuel stands in a container and gravity filters it ready for the next time.

K2

 

[dkwflight]

I rewired the ignition low voltage with a wall wart for 12 vollt. After discovering the low volt switch the engine seems like it will run on pump gas OK.

Dennis

 

[propclock]

Just for what it is worth, They were used on Model T's and run on 6v positive ground
but the polarity doesn't matter. They make an amazing spark! Fuel was iffy back then.

 

[a41capt]

When buzz coils fail, it is caused by the capacitor encased in asphalt in the box. They are rebuildable, and a replacement capacitor is inexpensive. If you find that your spark is weak and inconsistent, that may be the case.

Would love to see that beauty run if you’d post us a video!

John W

 

[doc1955]

I've repaired a few most of the time it is the cap that has gone bad.

 

[doc1955]

Ive made a few miniatures also from scratch.

https://www.youtube.com/playlist?list=PLp95TDxCzDrW89zqIXJfeRY5TK7dGSKD2

 

[dkwflight]

Hi
I got the engine to run on a premix gas with 40 to 1 oil. Very sooty exhaust
I could run this engine from room temp for 15 minutes or so.
WHen I try to switch to camp stove fuel it won't run.

 

[dkwflight]

A vid

 

[dkwflight]

 

[dkwflight]

I did not try to take the buzz box apart, once I found it would run.
Given enough 12 volt it ran continuously. That is when I found the interrupter switch on the engine. Not immediately obvious.
Dennis

 

[dkwflight]

Air bubbles in the water jacket.

 

[a41capt]

Air bubbles are one thing, milky lubricating oil or condensation on the spark plug is another! The intake stroke should draw coolant if there’s a leak, any other signs of leaking coolant?

John W

 

[dkwflight]

Hi
THis engine runs so sooty on regullar gas that the spark plug benefits from a cleaning.
It still does not run for extended times.
I am looking at a rimfire spark plug with a conventional ground.
They are cheap enough to try.
dennis
I will also try some non ethanol gas. with less oil