Is this lump power reducer in BF75 & BF100 inlet manifold?

[Henry Lapland]

Hi!

I am fixing my old Honda BF75 outboard motor and I faced lump in inlet manifold. First I thought it?s purpose is to reduce engine power, but then I found picture from 10hp version of the engine(BF100) and it?s inlet manifold looks exactly same.

I am installing BF100 cam shaft and bigger get main jet(#88) to the engine to make it 10hp. I would like also remove this lump, but what do you think, is it good idea to do so and what is original purpose of it?

Thanks!

 

[Scott Danforth]

the lump looks very specific, as in to either increase port velocity (improving power), or as a cast passage way. either way, I wouldnt remove it.

 

[Henry Lapland]

Thanks a lot Scott! I won?t remove it.