Originally Posted by MikeyOrange88
Understood. I was trying to carefully craft the wording to indicate that a higher vacuum (lower pressure) would increase the degree that the secondaries would open (wider opening, allowing more air in. Correct? My wording was probably poor, but I stated twice that they are operated only by vacuum.
Certainly not a carb expert, but I do like to drive the boat fast! I've learned a tremendous amount on TT, and continue to, as I read it almost daily. Thanks for keeping us straight.
Sorry, can't put stickers on the boat. Heck, I've not been able to drill any holes in it yet.
The secondaries are held closed by spring pressure so if the secondary diaphragm fails they will not go to full rich. For the secondaries to open, manifold vacuum must reach roughly 6 inches of vacuum before the secondaries will open (approx. 3/4 throttle). Vacuum at idle will approach 30 inches, and as the throttle blades are opened it will continue to drop to near zero vacuum at wide open throttle.
I haven't been able to add any decals to my boat, but it comes with a bunch from the factory so I think I am OK for now. I can still hit 44 MPH so no complaints.