Weird Speedo Issue 96 GTX

[etemplet]

I'm gonna start testing but this is hella strange. Speedo Operates to about 20mph. When I go over 20mph accelerating the speedo reading drops to 15 and may meander up to 20 or 25mph. If I accelerate to about 5500rpm the speedo may hold 20mph. As soon as I back off the throttle the speedo jumps up to the correct speed. When I add power the speedo drops down below 20 again. I did this about 5 or 6 times to prove it out. Both the INFO speed and analog speed readings are the same. This will be interesting. I am thinking it is an electrical issue as supply voltage at higher engine RPM is being affected. Might be the rectifier. I'll check the connections of course but the erratic behavior doesn't make me think the root cause is the speed sensor. As I said, this will be interesting.

This is my personal GTX that has a new engine I am breaking in. I'm finally getting to the point durning break-in were I can cut up some. I've very gentle during engine break-in. I gotta say, I think the 1996 GTX and all those with that hull design are GREAT SKIs.

 

[AKnarrowback]

Love my 97 GTX. Not super familiar with all hull designs but I'm not a fan of super aggressive hook up. My cousin has one of these super charged yamahas and it seems to be too "high strung" with even the most simple turns. But my GTX is smooth, mellow on it's cruising turns with a good grip if you move your body around a little.

 

[etemplet]

I checked the speed sensor (pick-up) in the back of the ski. ( Perhaps this picture will help someone someday.) LOL I got the voltage drop from about 8.8 to 5.5 volts while turning the wheel slowly. I checked the connections and I wanted to look at the connections to the gauges. I checked the voltage output at the battery terminals thinking that maybe I was getting a flucutation due to a faulty rectifier. Now I am wondering if one of the gauges isn't having an issue but since both drop off the same amount just doesn't seem like a gauge issue. They never stop reading, they just read inaccurately. Could be a bad wire, we'll see. I have gauges to swap. Still... the problem could be the sensor. I just hate replacing them. The quest continues....as usual. Touchdowns everyone.

 

[artr]

Since both gauges behave the same, I would suspect the sensor or the wiring that goes from the sensor to where it splits to go to both gauges. I would try the following tests. First look at the signal on the speed sensor tan-orange line (with your voltmeter ground on the black-orange line). I would guess it is a constant bias voltage or the sensor (like 12V) coming from the infocenter and does not change with engine speed. If that checks out and your ski is out of the water, maybe you can simulate various speeds by controlled blowing with a compressed air gun on the speed sensor to get it to rotate at a constant high speed and using the 30 second gauge wakeup function to power everything. If you get it to simulate the kind of error you see on the water, then maybe you can jumper in a spare working speed sensor (or the good speed sensor from your other GTX with longer jumper wires if it is out of the water also). I have never tried this myself but it may be something you may want to try to get to the bottom of the issue.

 

[1of500]

Stop fooling with the speedo wheels get the plug and play gps module from candoo pro. Those wheels only last a couple seasons before they stop functioning properly

 

[etemplet]

Stop fooling with the speedo wheels get the plug and play gps module from candoo pro. Those wheels only last a couple seasons before they stop functioning properly

I don't think this is speed sensor issue but it may be. I like troubleshooting to find the root cause It really is an economic issue with me and spending $160 on each sensor as I do a lot of skis. I'd rather keep $800 in my pocket. I always appreciate the help.

I actually have the Candoo on my RX.. it reads 5mph too slow. I might buy and extra one as a test platform.