Merc sync gage question?

S

SCORPIO

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Jun 1, 2001
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4810
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We're planning on purchasing a '89 Searay with twin 5.7l Alpha ones. The sync meter is not currently working (indicator reads fully to port). How does this device work? What is it connected to? My shop manual says nothing about this. I'm guessing it has a bad connection on the stbd engine somewhere, but I need to know where to start looking.
Thanks
 
Chris, I had that model synch gauge on my last boat. There should be a lead going from the unit to the port and stbd tachometer leads. I'd open the instrument panel and check those leads first.
 
Thanks! I figured it had to get a signal from either the tachs or the coils. I feel so unfamiliar with this boat. I know I have a lot to learn and figure out. I know every inch of my old boat so the newness factor here is a bit unsetteling.
Thanks for the help.
 
I'll be interested to hear if you get the gauge to work accurately. My sync favors the starboard engine...I think. I found a restorer that sold me a new original equipment sync gauge and that read the same way. At RPMs below 2000, it works evenly. Up at cruise RPMs of around 3000, the sync is a few hundred RPM off. I am confident in the tachs (they were replaced in the process) because of sound and fuel usage data. By the way, should you need a new sync gauge, I have an original equipment gauge for an '89 that I might part with. It works at least as well as the one in my 300.
 
Thanks Pl;ay, I'll let you know what I find as soon as we settle and I can start tearing into the boat.
 
I'm pretty sure that there is a sync module in between the tachs and the sync guage. It looks like a hockey puck and should be mounted under the helm somwhere. I forget if the signal goes from the motors to the sync module or the tachs to the sync module but either case the signal goes from the sync module to the sync guage. There is a small screw in the sycn module that allow for some minor adjustment if you sync guage is off a little bit.
 
WOW! In three years of trying to get an answer on this issue with all the local mechanics and even the Sea Ray dealer, finally a possible solution. I'll take a look next weekend and see if the "puck" exists. Sounds promising. Thanks.
 
This is what it looks like.
P5030905.jpg


Under the 'red' tab is the adjustment screw. You are supposed to use a non-metalic mini screw driver to make the adjustments...but I've always just used a regular mini screw driver. Make MINOR adjustments at a time.
 
That's it Dominic. It sounds like the connection to his stbd tach is the problem.
 
Great info guys! Thanks a bunch, this will save me alot of time chasing down wires. Now all I have to do is write the big check and sign on the dotted line and she's all ours.
 
I don't recall seeing that object behind the dash anywhere, but I haven't been looking for it either. Hopefully there's some type of adjustment feature somewhere to tweak this thing into shape.
 
dominic is right, and it usually the source of sync gauge problems. The things ar so prone to failure that the local Marine Max dealer keeps them in stock, a rare occurrence for Sea Ray parts.
 
Any idea what they cost Eric? At MM I doubt they are cheap.
 
I replaced one last year - I think it was about $80 for the sync module.
 
So am I understanding correctly that I need to add this device to my system (if it's not there) in order to adjust the syncronizer? If so, can you supply a name for the instrument?
 
quote:
Originally posted by SCORPIO

Eric, would happen to know the part number?

Click to expand...


For my '97 330 DA w/ 7.4L MIE, the original Sea Ray P/N was 144857.

I'm not sure about this but a quick check looks like the Teleflex P/N is 1508370P. A quick Google search looks like the current price range is $111 - $125.
 
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