Port Engine Accelerates Faster than Starboard

[BigBoysToys]

I have a 2008 Sea Ray 330 Sundancer with twin Mercruisers in a V-drive configuration. The boat is equipped with DTS. Both engines run great and I've had no performance issues however I have noticed a consistent yet slight lag on the acceleration on the starboard engine. If I were to do a test run from idle speed to WOT with the sync set on the DTS, the Port engine will climb to WOT slightly faster than the starboard engine. Its a very slight difference, maybe 100-150 rpm and the starboard engine always catches up within a few seconds so maybe I'm just being crazy. Under normal acceleration conditions, this does not occur but under hard acceleration, it is present every time. The WOT on the port engine is also about 70 rpm higher than the starboard (4710 vs 4640). This has always been the case since I purchased the boat. The following list of changes/maintenance have been performed over the last year with no noticeable effect. Props were replaced with new. Spark plugs replaced(all old ones looked great), All maintenance is performed religiously like oil changes, filter changes, etc.

The boat is a real steady performer and is in my opinion a 10 out of 10 when it comes to condition but this one thing just drives me crazy. Without Digital gauges, I doubt it would even be noticeable but if there's something that will correct it, I'd like to know. Dirty injectors? Weak fuel pump? (Under 400 hours on the boat), new spark plug wires? Any other ideas? Thanks!

 

[Hifirush]

I’m curious too.......

 

[Peter Schlossberg]

I think what you are describing is the normal operation of the synchronizer. That port engine is the master and the starboard is the slave. It takes a few seconds for the slave to adjust to the master throttle setting


Sent from my iPhone using Tapatalk

 

[BigBoysToys]

Really? Does that mean if I don't sync the motors on the DTS and instead just pin both throttles, then they may accelerate more evenly? I never accelerate so aggressively but I think it might be worth a test run.
Sent from my RM-927_nam_vzw_100 using Tapatalk

 

[bahamabreisus]

From what I understand, engine syncs should not be used at idle. The sync system is basically a clutch mechanism. The clutch will slip a little when accelerating. We use our system above idle but never firewall it from there. Bring RPMs up slowly, you should see a big difference in slip.

 

[BigBoysToys]

That is true. I never accelerate hard under normal use but the one or two times a year that I do a WOT test run, I do push it a bit. The point is to look for weaknesses so i can address them BEFORE they pose a problem. Under normal acceleration, the sync works very well. So if what you say is true, what I'm describing is normal?
Sent from my RM-927_nam_vzw_100 using Tapatalk

 

[Bucit]

Different boat and drives but my port motor lags behind 150rpms when pushing them wide open to get on plane. Been like that since I bought it.

 

[Peter Schlossberg]

You should be able to move the throttles together without the sync on to see if they respond differently.


Sent from my iPad using Tapatalk

 

[fwebster]

As you answer the OP's questions, keep in mind that he has a boat equipped with DTS. His synchronizer is electronic and has no clutches. Every new boat with DTS I've run with synchronizer on has a slight lag on the slaved side.....less than with a Glendinning or Sturdy, but the lag is still there.

 

[firecadet613]

Same lag on my DTS equipped boat, and I have Bravo 3s.