My speedo (Gaffrig) is at least 13-15 mph off (reads slow) on my 28 Daytona with twins. I checked the pick up hole on the front of the outdrive and it's clear. I even drilled it. Is there something else that might be throwing it off? What else could I check or do?

Buy a GPS Speedo. You tube is probably bent back. The more mine gets bent the slower it reads. I'm tired of replacing it. I plan on getting a GPS speedo.

Great solution, but don't want to spend $400-$500 right now when I could possibly fix the one I have. Maybe next year.

The Bravo Drive pitot system has never worked properly, with any brand of speedo, for very long. I know, I have been using & avoiding them on hundreds of new installations since the very first Bravo came out in 1988. The only way to fly, is with a Gaffrig Hi-Speed Pitot tube assembly, either the fixed or the newer spring-loaded pop-up version. They both use 1/4" I.D. black AeroQuip push-lok hose that goes forward to your speedo head. All speedo gauges, are nothing more than an air pressure gauge relying on specific air pressure provided by the water pressure pushing on the air trapped inside the pitot tube/hose. Therefore ANY leak in the hose connection at the gauge will ruin everything, especially in salt water. It will spray down your entire gauge system & cabin with water, salt, etc. AeroQuip push-lok hose AND push-lok fittings are the ONLY speedo parts to use on a go-fast boat. DO NOT rely on hose clamp or ty-rap connections. I have a brand-new, all stainless, Gaffrig Hi-Performance spring-loaded pitot assembly with hose, that I will sell for $195.00 plus shipping. Or...I can sell you a new stainless Gaffrig Hi-Performance standard pitot mount and tube with hose, for $75.00 plus shipping. Let me know if I can help. Thanks, Ed

My Gaffrig was also reading that much off. Twins and using the bravo pickup. Both of the hoses tee together inside the transom, then on to the speedo. Just found this weekend 1 of the yellow twist lock came loose and was bleeding off enough pressure to give the real low reading. Now it reads less than 1/2 mph off from my GPS.

Since they are just pressure gauges, hose ID's have no effect on accuracy.

I keep getting quite a bit of water in the bilge on the starboard sponson (Cat), I wonder if one of the tubes came undone and it's spraying into the bilge and giving the lower speed readings? I'll have to check that out..

Just out of curiousity, why would both outdrives be hooked up to the speedo? Wouldn't it only take one?

Easy to check since the hose is right at top.
Don't know why both are used since it should have no effect on the speed reading, other than the possibilty of still operating if 1 of the drive speedo hole does pick up a stick. All the Fountains I have seen are like this, while a couple other boats just use 1 of the drives.

I agree with Ed. I have a seperate pitot tube with my gaffrig and it always reads within 1mph of the gps. I wouldn't run the one on the drive. You can spend less than the spring loaded one (I do) but the down side is sometimes you have to fix it after you hit somebodies Coors light box or anything else in the water.

I had a non-spring pitot on a previous boat and it seemed like no matter how much I tightened it, that it would still move part way up and then the speed reading would be off. The spring loaded one makes more sense, but then the GPS speedo makes the most sense... Money, Money