boltonranger
Petty Officer 1st Class
- Joined
- May 2, 2004
- Messages
- 204
- 17.6 ft bowrider<br />- 3.7 I/O Merc.<br />I have a pitot tube and original speedometer.<br />The speedo seems slow to respond.<br /><br />I have replaced the pitot pickup (it snapped) and put the identical replacement in the original location. <br /><br />Here is what I found the next time out:<br />1. Still slow to read.<br />2. Pitot tube kicks upward at higher speed (30-35 mph)<br /><br /><br />I have done some reading since and here is what I discovered:<br /><br />1. Pickup is 3/4 inch lower in water than instructions called for.<br /><br />2. Pickup is mounted right on the inner edge of the innermost lifting strake. (Instrux. say mount away from strakes; prop etc.)<br /><br />3.The tubing to the speedo comes through the transom, drops about 10 inches in height; enters the wire harness and eventually goes back upward when it reaches the speedo. In other words, a very long, low spot in the line.<br /><br /><br />My question(s): Are these things I've mentioned affecting the speedo readout? <br /><br />Should I:<br />1. Eliminate the low spot?<br />2. Move the pickup towards the center of the boat?<br />3. Move the pickup upward as well?<br /><br />I appreciate your thoughts.<br />-br
