vacume at metering block ???

[Nucking futs]

Im trying to tune my carbs with a vavume gage and when i put it on the manifold port im reading 8-10" vac at idle. I put the vac. gauge on the metering block and im reading 5-7" vac. at idel except on the rear carb primary side it reads 0. Im thinking there is a problem here and i need to clean the metering block so it will read vacume. the front of the T ram is getting condinsation but the back side is not. Any advice besides its not right???Im going to take it off and clean it but just looking for and help. Also no power valves in the carbs.

[MikeF]

Tim, The vacuum fitting on the metering block is not for manifold vacuum, it is for "ported vacuum". This means at idle there should be no vacuum at this fitting. If the throttle blade is opened a little (kinda normal for a boat as we usually have big cams and do not like to idle at 700rpm), then you will get a signal at that hose fitting.
Ported vacuum is only used for vacuum advance (off idle) and other emission type devices that are not on boats.
Attach the vacuum gauge to manifold vacuum....base of carb....to get the correct reading.....for manifold vacuum.
Gonna have to think about the condensation Q a little more.......but now I gotta go help Randy put the engine in the CP19. :boxed:

[Nucking futs]

Thanks mike kinda figured that, but one is getting vacuum and the other is not. should i back down the blades on the one that is getting a signal?

[MikeF]

Check both to see if they are equal. Try to make them as the same if possible. I know.....it's fun. :skull:

[MikeF]

Randy called and is not ready. :crossx:
The condensation is likely cause the front carb is dispencing fuel and the rear carb (who's throttle blades are not opened at idle) is not moving fuel like the front.