Synched and linked

[Kirk Gibson]

Hello,
I have a problem with my new boat.
Twin F150 counter rotation four strokes.
Everything runs perfect but when I bring it down to about 4 or 5 mph the port engine is a little rough and shakes a little ...the starboard engine stabilizes nicely at 1000 rpms but the port then wanders between 500 and 800 rpms and shakes.
My local Yamaha dealer has it now and they are checking it out and after a test run and some checks they say it needs to be "synched and linked" .
Can anybody tell me what this means and what has to be done to do it.
They are going to do it under warranty but it will be next week and the mechanic isn't there today to tell me what all that means.
Thanks
Kirk

[99yam40]

Adjusting all the linkages and sync the carbs so that they open and move all the same amount.
The different cylinders are like all separate motors that are tied together with the crankshaft and you have to have all of them running exactly the same so they do not fight each other

[Kirk Gibson]

no carbs

This engine is fuel injection ...not carbs.

[Kirk Gibson]

Yes, problem fixed

Yes they had to adjust the throttle plates they were out of adjustment.
Runs great now.