Pretty simple from a wiring perspective. Mount the synchronizer, connect them to ground circuit and run a feed wire from each tach. Also connect to dash light circuit if needed. Do you have a suitable mounting location?

 

If you are talking the synchronizer gage - yes it is pretty simple. I think The OP is looking for something like the Glendenning synchronizers on my diesel 400DB. Turn it on and move one throttle and both engines respond together at the same RPM. This would require some additional equipment in the engine compartment.

 

Thanks...sounds too easy. How about the mechanical part?

BTW, I loved my 2 390's. Sold my first one (1988) after a divorce. A year later I bought a 1990 which I ran for ten years until the marina dropped it.
Nice heavy dry boat!

 

Installing a Glendenning mechanical synchronizer is a rather large project. Their site has all of the documentation to undertake such an installation.
http://www.glendinningprods.com/products/synchronizer
The Glendenning electronic synchronizer would be an easier install and adds many useful features. Here are the specifics for their electronic system:
http://www.glendinningprods.com/products/engine-controls/mechanical/178-smart-actuator-2

 

Synchronizing engine speed is a fairly simple thing without a glendinning. I would think an auto pilot would be more useful.

 

The mechanical version Glendinning isn't a hard project and is much cheaper than the electronic version. Give them a call, they're really friendly/helpful over the phone.

 

But, the original post was not about an Auto Pilot; he wanted to know how difficult it would be to install an engine synchronizer.

I've run a couple of boats with the new Glendinning electronic synchronizer and they are a great piece of gear. Installing one is not for the faint of heart and will take some time and some cost not included in the Glendinning box because you will need additional control cables to go from the synchronizer box to the engines.

I've had Glendinning on 3 boats and Mr. Glendinning's products, while complex, are some of the most dependable marine aftermarket products in the industry.

 

I had the same idea of adding auto-sync to my boat and found a competitor to Glendinning that seemed to have a better design - AccuSync by Sturdy Corp. It seemed like an updated design which made installation relatively easy and easier to use. It's been over 5yrs with it on my boat without issue and is a great option to have! No affiliation.

http://login.sturdycorp.com/gallery/detail.aspx?id=6630

 

Thanks for the responses all.

My previous two boats were equipped with AccuSync by Sturdy Corp. Easy to use and never any issues.

BTW...Autopilot is next.

 

I have the AccuSync on my boat, and you do not operate it like the Glendinning (according to the AccuSync manual). When I took it out for the seatrial, both the hired Captain AND the surveyor were convinced there was an issue with it and wrote the survey up as such. The difference is on the AccuSync you move both throttle levers as opposed to moving a single lever with the Glendinning. The AccuSync tries to sync the motors with the levers set far apart and actually will do it after a large bit of lag.....

 

Given the age of your boat I think you would be looking at the mechanical version. The electronic version seems to be run via new throttles at the helm? Or at least all the pics on the link above show it that way. So I suspect that would be a pretty major undertaking. You will need to run two take offs from the flywheels on the engines. They have a kit to fit the 7.4L engines on their website. I imagine it's a pretty involved job as you also have to re-route and re-configure the throttle cables to connect to the synchronizer.

I have the mechanical version on our boat and it is wonderful. The folks at Glendinning are wonderful. I asked them a question on the operation of mine and they responded quickly and in detail. They got me straightened out quick.

It's a wonderful option and I highly recommend it. Second only to a cable master, maybe the next boat will have that.

Take Care!!

 

Well this is how it shakes out. I talked to a Sturdy Corp. contact and they are out of the after market Synchronizer business. So, the only game is Glendinning and the mechanical version for me is definitely the best choice and not much different than my previous AccuSync by Sturdy.