Judson engine sychronizer

[guglielmo6160]

hello all again,
I have a very funky item on my flybridge called a Juson engine sychronizer, besides reminding me of the psychodelic 70's,, can someone tell me how it works, and how I operate it,
also believe it or not I found one on ebay and I want to put it at my lower helm as well, so if anybody can tell me how it hooks up, (im sure its on the coils etc, but really not sure) I would appreciate any info on this
item as it is interesting

[ready123]

You don't operate it, it is a visual display of engine speeds relative to one another. It is to guide you to synchronize the engine speeds....
generally port light flashes red means the port engine is too slow if starboard flashes then it is too slow. Geen light in middle flashing then both engines are at same speed... that is for a three light system, I have a Guest #1500 on my F 32 that works as above.
From your comment about psychedelic 70's I'm guessing it is working... lucky you.
What model is it? Any photos?

You likely don't need one at the lower helm as it is much easier down there to listen to the engines to get them in sync.

[gjrylands]

Hi Bill,
The Judson engine synchronizer is like 2 timing lights in one lens. It is a very simple instrument to operate. When it is on each light in the len, or eye blinks as the engine fires. When the engines are running at different RPMS the light will appear to blink. As the RPMS of the engines approach synchronization the blinking of the light will slow until it is a steady glow. At this point the engines are synchronized.

The installation of the Judson engine synchronizer is simple. There are 4 wires coming off the synchronizer, 2 red & 2 green. The green wires are for the starboard & red wires for port engine. Both engines are connected to the synchronizer in the same manor. Start with the port engine. The ignition wire is removed from the ignition switch. If there are more then one wire on the switch terminal, remove only the wire leading to the coil. Connect one of the Red wires from the sychronizer to the ignition wire leading to the coil. Connect the other Red wire to the ignition switch. Do the same with the starboard engine, but with the green wires. When finished, if both halves of the indicator light are not of equal brightness, interchange the connections of the red wires for the port switch only.

I have a Judson engine synchronizer that I removed from my boat when I installed an engine synchronizer with digital tachs. If eBay doesn’t work out, I’d be willing to part with mine. If interested send a PM.

[guglielmo6160]

Im assuming its working, the last time I was on the flybridge, it turned on via a toggle switch and appeared to have flashing, spark type lights in the glass in the front , I did manipulate the throttles and the frequency of the lights changed, but I wasnt looking for, or didnt notice a green light, this light would be in the center? , the exterior is badly pitted, but it still seems to work, my plan is to remove it and refurbish it, as I have never seen one of these,
the other day I was on ebay looking around and I saw the exact one, so I bought it and plan on using it at my lower station,
it comes with pigtails so I would like to know how it attaches

[guglielmo6160]

thanks Ger,, that helps,,,
Ill be in touch if it dosent work,
I figure its a neat item

[gjrylands]

Bill,

One of the wires is connected to the ignition wire. The other wire is connected to the negative side of the coil.

I have done some research on the wiring of the Judson engine sychronizer and found a paper that showes that you cut the ignition wire going to the starboard engine. You then connect one of the 2 wires green wires from the sychronizer to each end. The same is done with the port, but with the red wires. This simple means that the ignition wire runs through the sychronizer before to goes to the engine.

I'm not sure, but I think that this is the correct wiring. To be sure, check how you your sychronizer is installed.

[lakeguy72]

I had a Judson for 26 years on my F-32 and only recently changed to a more easy to read Faria dash unit.
My Merc 233's had conventional points/condenser ignition and I had no problem until I switched to Prestolite Electronic distributors. The Judson even with #10 wire caused the voltage to drop to 7.5 volts @ the coil(no external resistor on this engine). Conventional ignition systems can operate on less voltage than electronic systems. When I disconnected the Judson the voltage came up. I've heard that it takes 10.5 volts minimum for electronic systems. On my first trip out with new distributors both engines quit within minutes of each other. I used the lower station switches(not in the Judson loop) and the engines ran perfect.
I have the manual and the old unit which is yours for the shipping charges. The manual specifies a different hookup procedure if you have Chryslers.
Lakeguy

[jimbo36]

If Bill dosen"t want the Judson sync mentioned I sure would be interested for my F36 Tricabin. I have had one or two over the years, on other boats I have owned and would love to have one. Jimbo36,

[gjrylands]

I have a Judson Engine Sychronizer That I removed from my 69 31' Trojan. It's in great condition. If you want it I will sell it for $25 + shipping. Here's what it looks like.





guglielmo6160 has first chance to buy. If he doesn't want it than jimbo36
will get the chance. Send a PM if intrested.

[guglielmo6160]

appreciate the offer, but as it stands I have three with the one Im getting from Lakeguy, so you can offer it to the next guy,
I appreciate the offer , thanks very much,

[guglielmo6160]

well I decided not to use these synchronizers, I dont like the way they hook up, I think if they fail, your engine fails, and I dont like that,
so I will use a better tool,,, my hearing, maybe the 30 plus years of being a mechanic will help me with that,,,
thanks to all, I will keep them for asthetics as I find them interesting