MPH is not working on 1996 SLT 780 MFD??

[mwenholz1]

Hello, I just got my rebuilt 1996 polaris slt 780 back in the water yesterday and everything on the MFD is working except the MPH. Can someone tell me what may be the cause.

Thanks

Mark

[Technical Support]

Re: MPH is not working on 1996 SLT 780 MFD??

the tube behind the gauge hooks up under the drive shaft behind the engine to a small nipple in the hull, water pressure pushes into the tube to make the speedo work.

[mwenholz1]

Re: MPH is not working on 1996 SLT 780 MFD??

Ok, quick update here. I now know that I need to verify that the pitot tube is connected or not blocked at least. Does anyone have pictures of where this tube connects at both ends? Also, every once in a while I will get a reading of lets say 5mph. So at least I would think it is connected if I am getting that. Maybe it is not pointed correctly at the rear end by the jet pump?

[Technical Support]

Re: MPH is not working on 1996 SLT 780 MFD??

Nipple on the back of the gauge and under the drive shaft by the grease fitting.

[mwenholz1]

Re: MPH is not working on 1996 SLT 780 MFD??

Ok, so If I find both of those to be connected ok what should I look for next. Can the tube or pipe that comes out the back near the jet pump be positioned incorrectly? Or is that something that is set in place and can't be moved. Also, I'm assuming the tube that connects in the front and the back is clear?

[Technical Support]

Re: MPH is not working on 1996 SLT 780 MFD??

Make sure the fin under the ski that the tube hooks up to inside the ski is inline with the hull and not angled to one side.

[mwenholz1]

Re: MPH is not working on 1996 SLT 780 MFD??

Everthing appears to be correct on the outside of the ski. Can that even be adjusted? It appears to be a solid piece. I am looking to remove the tube inside from the MFD to the bottom nipple to make sure the hose is just not kinked.

[mwenholz1]

Re: MPH is not working on 1996 SLT 780 MFD??

Update: I removed the tube from the MFD end and blew in the tube. My wife stood at the rear of the ski and could feel the air come thru the tube. So what could the issue be now. The tube appears to be good.

Thanks

Mark

[Technical Support]

Re: MPH is not working on 1996 SLT 780 MFD??

The MFD could be bad

[mwenholz1]

Re: MPH is not working on 1996 SLT 780 MFD??

I would find that strange but possible. All the other functions work perfectly.

[Technical Support]

Re: MPH is not working on 1996 SLT 780 MFD??

It’s a very simple set up, water pressure pushes air through the cable to the cluster. Blow compressed air through it. You should invest in a manual all the test procedures are in it.