2003 Honda BF90 vacuum hose routing

[venuspie]

Just picked up a 2003 pontoon with a 2003 Honda BF90. It is carbureted, not sure when they started fuel injection. Fun learning how to rebuild and sync the carbs. My question is vacuum hose routing. I found a couple of ports on the silencer part of the airbox and one coming out of the engine. Not plugged off, just open. Also found a small piece of vacuum line that was tee'd off that had fallen off from somewhere. I have a service manual but can not find the vacuum diagram anywhere. I don't believe there are too many vacuum lines to work with but would like to get it right. Thanks in advance!

 

[ahicks]

Are you talking about the large (maybe 5/8"?) crankcase vent line that runs from the upper part of the valve cover to the "muffler"/silencer?

The only vacuum lines I can think of are located on the back sides of the carbs, which are on sort of a manifold made from tubing, that collect vacuum for use on the dash pot that keeps the engine from returning to an idle too quickly (causing it to stall).

The only other lines, that are often seen dangling in various places, are the drains routing fuel from the carb when the float bowl drains are opened. Pretty much useless, they're generally not maintained, are often removed and tossed.

If I've missed the mark here, a picture of what you are talking about might be worthwhile to post. -Al

 

[venuspie]

Thanks for the reply! I’m not talking about the large breather hose or any hoses connected to the carbs. Their is a port on the engine beside the oil filter and 2 ports in the plastic air silencer part of the intake. I’ve attached pictures showing what I mean. Also attached is a pic of the hose I found lying loose in there. Seems to have no ill effect being unhooked but wanted to know what they were for.

 

[venuspie]

Pics

 

[ahicks]

The vinyl line with y and t in it is likely one of the drain lines I mentioned. You can pitch it without fear. The ones on the silencer are drains, and the other, coming from the block, is a vent. No need for any action on your part.

 

[venuspie]

Great! Thank you for the help!