airguide speedo calibration

Sorry guys, I was wrong on two accounts. Start to end slalom course is: 259 meters, 850 feet. ADJUSTMENT: The allen socket screw in the front of the instrument is used to precisely adjust the speed indication with the boat underway.
     Refer to the speed and time chart below, as providedby the American Water Ski Association's Official Tounnament Rules, showing the time required to complete a run at a given speed.
     Run the boat through the slalom course at an indicated speed of 36 MPH and have your observer check the time by stopwatch. If the time is between 15.88 and 16.28 seconds, no adjustment is necessary. If the time is less than 15.88 return to the course 36 MPH and adjust the reading upward. If the time is more than 16.28 seconds adjust to a lower reading. additional runs may be required for exact reading or to match reading on dual installations.
     The table is based on a slalom course of 259 meters or 850 feet and this length may be used as the basis of a measured course where a slalom course is not available.

                  SLALOM COURSE
SPEED              TIME           
MPH   KMPH       SECONDS          TOLERANCE
22     36          26.33        25.75-26.95
24     39          24.14        23.65-24.65
26     42          22.28        21.86-22.72
28     45          20.69        20.33-21.07
30     48          19.31        19.00-19.64
32     51          18.11        17.83-18.39
34     55          16.95        16.65-17.25
36     58          16.08        15.88-16.28

Sorry, Don was quoting off the top of my sunburnt head, didn't have my chart, or a abbacus in front of me. When I learn how post a pic. link on here, I have quite a few Airguide sheets, new, and old. Maybe I'll just let Keith do it for me!

'79,

No, they are a bit different in that the dial is evenly divided, without the exagerated spacing between 25 & 35 mph. I'll try to post a picture of the gauge face later tonight.

By the way, congrats on the success of the re-build! How does that hull react at over 50?

Don,

Do those speedo's look like the stock ones? The majority of the time I won't be running it above 50 but I'm looking at increasing the prop pitch and the speed will pick up so those 70 mph mau come in handy

An Airguide tournament speedo. is calibrated between the first and last bouy on a slalom course, (800 ft.). The driver passes the first bouy at 35 m.p.h., the judge in the observers seat starts the stop watch, the driver passes the last bouy in 26.3 to 26.6 seconds. If not the driver repeats and the speedo is adjusted accordingly. I'll try to post the chart in the next few days.

I was out over the week-end and did some runs in perfect conditions to compare speedo's with my buddies Ranger and to see how well the engine mods turned out (we did this before with the stock engine and I got smoked out of the hole and on top end)

Well my speedo reads 7 mph slower than his. Can I adjust this out on my speedos or is it to much of a change? Also when I peg the speedo's will I have to recalibrate again?

As for the speed runs, the results where a little different this time around. I ran against a late 90's Ranger that will do 70 mph.
I left him coming out of the hole and he had my at 58 mph on his speedo on top end.

Now I have to decide to use the 13x13 3-blade or get a new 4-blade with increased pitch. And the exhaust note is SO SO SWEET, even with the mufflers.