Volvo Penta 5.0 GXI with SX-A: Speedometer reading zero

[dhardest]

My speedometer has been reading zero for a while, and I plan to finally address it. I've read that the pitot tube on the leading edge of the stern drive can get clogged. I've googled it and looked on YouTube and have seen some other model outdrives where compressed air is used to blow the debris out of the tube, but usually there is a joint slight downstream in the tube that is disconnected to give the debris a place to exit, otherwise it just gets pushed further up in the tube. However I haven't found where to disconnect the tube on the SX-A. Can anyone throw me a hint as to where this might be?

 

[StingrayMike]

Why not remove the tube at the speedo and blow it that way?

 

[dhardest]

That's a good idea. Guess I can try that this weekend.

 

[GA_Boater]

Too much pressure and the tube may blow out between the speedo end and the lower unit. Be aware.

 

[skydiveD30571]

If you pull the drive off, you'll see where the speedo tube connects to a white plastic joint at the bottom left of the pivot (below and to the port side of the exhaust ducting. When the drive is installed, it flushes up against this joint to form the routing from the speedo hole to the speedometer.

 

[dhardest]

Ok, thanks for the clarification. So basically no intermediate point to disconnect and clear the path without pulling the drive off (which I'm not sure I want to tackle unless I really have to). I'll try the idea about blowing from way up at the speedo gauge (and be careful not to put too much air pressure in) and see if that works, and then go from there.

Afterthought ...... does the plastic tube mate up on the inside of the transom to a flexible hose, and would that be a good place to disconnect? May be tough to get to that spot but seems worth a try.

 

[skydiveD30571]

Ok, thanks for the clarification. So basically no intermediate point to disconnect and clear the path without pulling the drive off (which I'm not sure I want to tackle unless I really have to). I'll try the idea about blowing from way up at the speedo gauge (and be careful not to put too much air pressure in) and see if that works, and then go from there.

Afterthought ...... does the plastic tube mate up on the inside of the transom to a flexible hose, and would that be a good place to disconnect? May be tough to get to that spot but seems worth a try.

Yes the plastic piece has the speedometer tube running from it to the gauge, but I doubt there's access to it without pulling the drive.

Side note: Are you pulling the drive regularly for maintenance? It should be part of your routine maintenance, and doesn't take more than half an hour or so.

 

[Thalasso]

Looking at the drive from the rear. The plastic connection is on the underside on the left. You don't need to pull the drive. The plastic usually breaks where the tube connects to it

 

[dhardest]

Looking at the drive from the rear. The plastic connection is on the underside on the left. You don't need to pull the drive. The plastic usually breaks where the tube connects to it

I'll definitely check it out this weekend to see if I can get to this tube and assess breakage, or if it can be disconnected to clear the path.

And I'll also learn about pulling the drive. I've always assumed this would be beyond my skill level for doing successfully without messing something important up, but if it doesn't take that long, then sounds like something I should learn how to do.

 

[Thalasso]

I'll definitely check it out this weekend to see if I can get to this tube and assess breakage, or if it can be disconnected to clear the path.

And I'll also learn about pulling the drive. I've always assumed this would be beyond my skill level for doing successfully without messing something important up, but if it doesn't take that long, then sounds like something I should learn how to do.

Find your drive here and it will tell you all you need to know
http://boatinfo.no/lib/library.html

look here in the stickies for more interesting info
http://forums.iboats.com/forum/engi...68-must-have-technical-information-for-diyers


Should be done yearly.
1. check for water in the bellows.
2. grease the input shaft
3. Replace the o-rings (2)on the input shaft at the same time along with the water passage o-ring/gasket.
4. replace the o-rings on the drain/vent and dipstick
All of that stuff can be gotten here in boat parts and acc.

This is what broke on mine. See the barbed end. I wouldn't worry about fixing it.There nowhere close to being accurate If you blow air in the tube to free it up,do it from the speedometer end.

 

[dhardest]

Find your drive here and it will tell you all you need to know
http://boatinfo.no/lib/library.html

look here in the stickies for more interesting info
http://forums.iboats.com/forum/engi...68-must-have-technical-information-for-diyers


Should be done yearly.
1. check for water in the bellows.
2. grease the input shaft
3. Replace the o-rings (2)on the input shaft at the same time along with the water passage o-ring/gasket.
4. replace the o-rings on the drain/vent and dipstick
All of that stuff can be gotten here in boat parts and acc.

This is what broke on mine. See the barbed end. I wouldn't worry about fixing it.There nowhere close to being accurate If you blow air in the tube to free it up,do it from the speedometer end.

Thanks for the guidance on yearly maintenance.

Are you suggesting not to worry about fixing the speedometer at all?

 

[Fishhead-1]

I think most everyone here has chartplotters or gps to measure speed accurately

 

[Thalasso]

Thanks for the guidance on yearly maintenance.

Are you suggesting not to worry about fixing the speedometer at all?

Yes.I wouldn't worry about it. I didn't fix mine. For most people boating isn't about how fast you think your going to need a speedometer that's usually not correct.
If the plastic fitting is broke,find the rubber hose and just plug it and go boating.

 

[dhardest]

I gotcha. I got the boat out of storage yesterday and found the plastic part pictured above. It's not broken but I did notice that there's dirt or some other material plugging the pitot hole. I'll break that up and will blow air through to blow it out. I would guess that would work. If not you're right it's not a big deal. Thanks.