1/4" rubber hose to lower leg/ speedo ??

CapCramer

Seaman Apprentice
Joined
Feb 7, 2009
Messages
47
'92 70hp Force on a Bayliner. I followed the rubber hose from the speedo back to the engine and it looks like it goes into the front of the lower leg. Is this for the speedo that doesnt work? If so how does it work without the pitot? Cant find anything in the Selco book. Factory mounted speedo. One other thing, why is there a 5/8" wide plate diagonally across the front of the carb from say the 12 o'clock position to the 3 o'clock position? Some engines in the book show a plastic baffle about 5" square in front of the carb. Wondering if I am supposed to have that. This is the 3 cyl with a single carb. Thanks all.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 1/4" rubber hose to lower leg/ speedo ??

You must look very closely to see it but there is a small hole in the front of the leg. It will be between the cavitation plate and the gearcase torpedo.This is the impact tube for the speedometer. It works the same way as the pitot tube but it will not get fouled as easy and of course will not kick up when you hit small debris. It will be a little more precise because the engine leg is always in the center of the boat and always traveling parallel to the water movement. An offset pitot tube will vary water pressure (and thus speed reading) when the boat turns, and the variance will be dependent upon the amount of offset from center. A pitot tube should net be mounted in the center of the transom because of the possibilty of disturbing water to the prop.

Can not help with your carb though.
 

CapCramer

Seaman Apprentice
Joined
Feb 7, 2009
Messages
47
Re: 1/4" rubber hose to lower leg/ speedo ??

Thanks Frank. Darn if I would have found it without ya! Looks plugged so I will use compressed air or a fine wire. I think you saved me some $$ for not buying a pitot tube. Right above the gearcase, small as heck but it is there. Thanks again!
 
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