Fairbanks Morse Z w/o AB33 Mag

Bojac

New member
I am working on a Fairbanks Morse Z, 1 1/2 hp, open flywheel but I lack the AB 33 magneto. I've seen videos of the engines running without the mag using a battery and coil and perhaps a micro switch. How is this set up? Any hepl would be greatly appreciated.
 
Re: Fairbanks morse Z w/o ab33 mag

I am working on a Fairbanks Morse Z, 1 1/2 hp, open flywheel but I lack the AB 33 magneto. I've seen videos of the engines running without the mag using a battery and coil and perhaps a micro switch. How is this set up? Any help would be greatly appreciated.
There is currently a discussion here:

https://www.smokstak.com/forum/showthread.php?t=173715

Though the original poster is working on a Hercules, the principle is the same.
 

AngrySailor

Subscriber
Re: Fairbanks morse Z w/o ab33 mag

I've been thinking about glueing a magnet to a cam gear or flywheel and using an MPU to trigger something like a readily available automotive ignition module like an HEI... could be done discreetly and is pretty simple to time...
 

Bojac

New member
Re: Fairbanks morse Z w/o ab33 mag

Thanks. My latest idea is to build a bracket and attach a long levered micro switch in combo with mag and buzz coil. Does this make sense?
 

Pat Barrett

Subscriber
I think the AB33 is a flick mag, I've seen folks take a worn out string trimmer and remove most everything but the crankcase, crank, coil and flywheel and mount some tension springs in the correct position to where when the finger pushes the crank, the magnet alignes with the coil and when released, the magnet flies away from the coil, creating a spark. Cheap to find, just takes time to figure out and mount. Only works with spark plug engines.
 

AngrySailor

Subscriber
Re: Fairbanks morse Z w/o ab33 mag

Thanks. My latest idea is to build a bracket and attach a long levered micro switch in combo with mag and buzz coil. Does this make sense?
Yes, but your micro switch must be able to handle the current draw of the buzz coil AND deal with the DC arcing as the contact breaks... Maybe use a relay controlled by the micro switch or just make a friction contact with plenty of contact area which is easily cleaned:shrug:
 

forney00c

Member
Re: Fairbanks morse Z w/o ab33 mag

We have a 1918 6 HP FBM converted to spark plug. A bolt was put into the can gear, much like the trip for an AB33 equipped engine. A plate was mounted where the mag would be and a lever which held the insulated switch was mounted on that plate. Now whenever the bolt on the can comes around, it hits the switch, firing the coil. The lever is really nice because it allows us to retard the timing to start and then advance it once the engine is running.
 

Blueflame

New member
Re: Fairbanks morse Z w/o ab33 mag

I'm setting up my F-M 3hp the same way. It's my first engine, so I really don't know what I'm doing, and it hasn't run in years. I'm getting consistent spark, when I check the plug outside the engine, but I can't get it to run. Can you please tell me 1) how far should I open the fuel valve, and 2) how far do you move the timing, relative to TDC, to start, and to run ? I'm using 91 octane gas, because I can buy it locally with no ethanol. Thank You !
 

AKMark

Subscriber
About a quarter turn on the fuel, squirt some gas in the front of the mixer and see if it fires. You may have a plugged check valve it's attached to the fuel line inside the tank. Just pull the fuel line off and see if the ball in the valve is not stuck. Sometimes it helps to have someone cover the air intake on the front while you spin it over. Good luck with it they are fun engines.
 

Blueflame

New member
Hello Again. I'm back on this project ! The best results I've had were to get it to run ( sort of ) for about 6 or 8 seconds, while my buddy was squirting gas from a spray bottle in to the air intake. I had gas an inch deep in the little tank, but it wouldn't draw that in. We tried covering the intake, as you suggested, to prime it, but it seems very sensitive to flooding. I believe there is no check valve in the line from the little tank...
true ? Having heard it try to run, I'm confident that with enough help It will run again ! Thanks again for your Help !! PJB
 

Andrew Mackey

Moderator
The small reservoir on the mixer does not have a check. The 1/4" tube that goes into the main tank has the check at the bottom. To start, the reservoir has to be nearly full to the top. if you overfill, with the fuel valve open, it will flood the mixer and also flow out past the hole in the reservoir that the fuel needle goes thru. Yes, the fuel settings are pretty sensitive on the Zs, am 1/8th turn makes a great deal of change. These engines were made to starton gas (reservoir) and switch to kerosene (main tank). You can run on straight gas if you want.

try removing the fuel adjuster and running a long needle thru the opening. There may be some crud in the jet. Blowing air thru the openning may clear it out too. To start, fill the reservoir to the point where gas flows out the adjuster mount hole. Open the adjuster about 1/3 turn from lightly seated. be sure the main adjuster is CLOSED. Manually choke engine until gas flows out the intake, then crank engine. A question here - is your snifter valve (spring loaded plate mounted in front of the mixer) working) You should hear it vibrate as it opens on the intake strike. if that plate is missing, broken or if the spring is to weak, the mixer will not draw fuel. If your engine is not drawing fuel from the reservoir, I believe you can do the following: Remove the main jet and fuel line assembly from the carb, by removing the 2 screws and the retainer. Remove the reservoir fuel adjuster valve. Using a 3/16 punch, drive out the reservoir pick up thru the main jet openning, into the reservoir. You then can remove it and clean out the pick up and the jet. To re-install, put in reservoir and make sure pick up is nearly straight down and that the jet end is started in the mounting hole in the mixer. Install needle valve screw, and GENTLY tap with a small hammer until it is seated. Re-install main jet.
 

Blueflame

New member
I do not have a big tank, so I am trying to start this just with the small tank ( reservoir ). The shut-off for the big tank is in place, cleaned, and shuts off completely. I just removed the main tank adjuster assembly, and the reservoir needle, and shined a light thru. The reservoir jet looks clean, round, and the same size as the main tank jet, so I did not remove it. With everything apart and clean, I experimented with sealing all holes except the reservoir valve, and blowing in to the mixer. After doing that, I'm suspicious that I may not have been closing the reservoir valve completely, and therefor might have had it open 1 1/2 turns, when I thought it was 1/2 turn. (That adjuster turns very hard for the last turn ). The snifter valve seems to be operating correctly...I hear it vibrate as I turn the engine over. Tomorrow I'll reassemble and try again ! Thanks Again for your help ! PJB
 
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