Mercruiser Twin Inboards 5.7 EFI Horizon

[Harley558]

I have a 2000 Mercruiser 5.7 EFI Horizon engines. The engines don't appear to be sycronized. I have to give more RPMs to one engine to get the dash guage to sycronized. I would say about 300 to 400 rpms. My Starboard engine is the one that appears to be out of sync.

I tried to look up how to adjust the throttle cables to sycronize the engines however, I can;t find anything on it.

How do I sycronize them?

 

[JustJason]

Re: Mercruiser Twin Inboards 5.7 EFI Horizon

The first thing to do is to check the engines with a known good tach. Its simple to hook up but you may want 2 shop tachs. Are the drive both standard or is 1 counter rotating? When the engines are wide open, does the boat pull 1 way or the other? (ie-if the right engine is 400rpms higher does the boat list/push left?)

 

[HT32BSX115]

Re: Mercruiser Twin Inboards 5.7 EFI Horizon

Howdy,

Assuming the engines are both producing equal power and are in the same state of "tune" your tach(s) will probably never be perfectly the same. You may also have a "bad" tach too...

You would need to get them fairly close, then sync them by "ear" anyway... (like tuning a musical instrument!)

(you do it the same in a twin engine airplane too!)



Regards,

Rick

 

[Harley558]

Re: Mercruiser Twin Inboards 5.7 EFI Horizon

I purchased the boat last year just before the end of the season. 69-It's a 2000 Sea Ray 310 Sundancer. I had it surveyed and everything was O.K. During storage, I cahnged the plugs, oil, fuel seperator, etc... Now I can't get the Satrboards engine to peak. It strggles to past 3,400 3,600 hundred RPM's. I was wondering if during all the maintance, I may have stepped on on the throttle cable or something to knock it out of sync. I can't find any info on how to sync them together. If it was all good at the end of the season, then I would guess the problem has to be some type of adjustment.