View Full Version : speedo problem in 84 S&S

08-16-2007, 05:16 PM
I have dual speedos and they have quit working.

The left one has completely quit and now the right one failed too.

The right one sucked up a ton of pine pollen off the surface of the lake. It seems hard to believe but this fine junk also plugged up the intake from the lake.

I took a needle and cleaned out the pick ups and now the right one works-sort of. It takes 20-30 seconds to develop an accurate reading and gets there by creeping up very slowly to the right speed. Annoying, but I can live with it if I have to.

The left is just dead. No cleaning out of pickup has improved anything. Any ideas on what to do next?


08-16-2007, 05:24 PM
The Speedo pickups on the back of the boat are clogged
Remove the Pick up line and blow air via a airgun backwards though the pick ups. They should flow clearly. DO NOT blow air via a higher
pressure source toward the speedo head. You should be able to move the speedo guage to approx 7 MPH with your own breath via the hose. USE nothing more that that because you DO NOT want to blow the diaphram out. You can also replace the speedo pickups on the boat for about $12 each

[email protected]

Dan K
08-17-2007, 04:03 PM
I did exactly what Jim described on my boat earlier this year and the speedos work great now. Just remove the speedo hose at the dash and blow out the line to the back of the boat.

08-27-2007, 09:54 AM

Went down to follow that advice and then got a little lost.

My dash has seperate hexagonal unit which is mounted on the dash and contains all of the gauges. Do I have to get into that to find the end of the speedo line? If so, how do I do that?

I am also a little confused on the blowing part. I get that I have to find the front of the line. What does it connect into? Do I blow from the front to the back after I disconnect the line at the front? If so, how does that push the speedo up to 7 mph?

Lastly, if I am going into the dash unit, I have never had lights on my Speedos (I have lights on all of the other gauges and switches, but not the speedos.) This has not really been a problem, but while I am at it........

ProTour X9
08-27-2007, 09:56 AM
speedo problem

Ask Maristar 210 he should know:noface: :noface: :uglyhamme :o

08-27-2007, 12:17 PM
There are 2 buttons on the top and 1 on the left side of the console around the dark trim ring. Unsnap the buttons, they cover screws. The instument panel will now pivot toward you, there are two detents on the bottom, so as you are pulling it toward you, drop it down off the detents, the gauges are exposed. Remove your speedo tubes and blow.

08-27-2007, 12:18 PM
Sorry, (duh) unscrew the screws first.

08-27-2007, 12:21 PM
Also, there are bulbs in the speedos, maybe you will find yours are burned out.

08-27-2007, 12:27 PM
One more note on this (having gone through the same thing earlier this season with my prostar 205V) -

I found after clearing out the gunk in the pickups that one of the speedos was slow to respond, as you describe. I just cleaning it out again, and it slowing improved. Can't explain why, but after a day of skiing on the lake it was just as quick as the other one. Maybe there was still some blockage that got pushed away by normal use. I dunno. Just wanted to let you know that I saw the slow gauge effect too, and I think it was also just due to the silt in the works.

Good luck with this.
P.S. there's a lot written about this on TMC! It's a pretty common problem. Search around and you'll find tons of threads on this.