www.iFourWinns.com

This summer I struggled with getting and keeping my engines synced at low speeds (just above idle).

The issue is when I put my engines in gear and throttle up just a bit my starboard engine wants to go too fast or stay at idle speed. The port engine seems to be the normal one of the two. I can’t recall the engine speed at this time, however, this problem occurs when I’m trying to maintain a boat speed of approximately 7mph. Once I speed up and put more of a load on the engines the problem is gone.

I have played with my throttle setup and have gone as far as to measure throttle position at the engines at various lever positions. Everything with this regard seems to be perfect. Also, outdrives and props are in good condition.

I have a suspicion (guess) as to what the problem might be, but I’m going to hold on to this for now as I would like to hear some fresh thoughts.

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2004 - 288 Vista
Twin - 5.0 Volvo Penta GXi DP

Have you verified that it is not just a false reading from your tach?
Does the boat try to turn on its on when they are not in sync?

Just a thought.

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The Dance II
2007 278 Vista
6.2L Mercruiser

I am 100% sure it’s not the tach or synch gauge. I can hear and feel it.

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2004 - 288 Vista
Twin - 5.0 Volvo Penta GXi DP

I would suggest checking the Idle Air Circuit (IAC).
Easy to remove and clean. Also clean the throttle body where it is inserted.
My guess - it is not metering air flow properly at just off idle due to carbon buildup.

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The Dance II
2007 278 Vista
6.2L Mercruiser

Interesting... I’ll have a look at that.

Thanks

Now I just have to wait for spring

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2004 - 288 Vista
Twin - 5.0 Volvo Penta GXi DP