40hp 1998 yamaha carb. questions

[skipjack]

I just pulled my #2 carb apart for cleaning and have a question about the prime start assembly operation. there are two rubber hose from my prime start assembly. I have read the hose that runs to the top of the intake manifold feeds fuel to all the cylinders thru a drilled passage in the manifold, as long as the prime start valve is open. Just a automatic choke I figure. The hose that runs to the top of #2 carb also has fuel controled by the prime start system. Is this #2 carb hose just an additional enrichment system for #2 along with the manifold passage, or am I missing something?
Also I have a question about carb. sync. I always figured this meant all carb plates open and close the same, then I read the procedure in my Seloc manual and got lost. To make a long story short if I adjust top and center plates closed when bottom plate is closed (bottom is not adjustable on my motor) then my carbs are in sync right? The Seloc make it sound like one should be open more than the others, at least that is my take on it.
I am trying to get this info before I leave tomorrow. My boat is 150 mile south of here. no computers or help there.
You people seem very well informed and have a great site here. I will appreciate any info anyone has to offer. Many thanks to all

[99yam40]

The hose that runs to the top of #2 carb from prime starts system is just a place to pull fuel rich air off the top of carb #2 to mix with the fuel in the prime start system while it is activated.

you are correct on the syncing of the carbs , they make it way to confusing. All should be closed at the same time.

[skipjack]

Thanks for the info. I got a little confused with the directions in the Seloc. That hose issue blew my mind too. Dont think I should have any problems now. I figure a good job is at least 60% self confidence.