Suzuki Outboard Speedometer

[Karnic]

View attachment 72893

Hi Guys.
I have a Suzuki Ob 115 with a speedo exactly as the one in pic. Lately i was having an issue with the speedo and would like your views . While underway the gauge needle would not go up but when i accelerate the needle starts marking ( go up ). Before as far as im concerned the needle would mark even at slow speeds ex 15 knots but in order for needle to start going up i have to accelerate hard. After accelerating hard needle will start marking. Also needle sometimes toggle a bit up and down.
I would like to know if Either gauge is not working properly or the hole on the outboard is clogged. However i inserted a needle in the hole of the outboard to unclog it a bit but to no avail.
What Should i do? Do you think i should try to unclog the hole on outboard if its from there. Needle only entered hole few cm's. Should i try to unclog more or gauge is faulty?
Thanks

 

[Keith-i]

I would think the most likely cause is a blockage in the tube somewhere. Pushing a needle/wire up might just push it further upstream. Fitting a new water tube from gauge to outboard might be the easiest, or maybe disconnect at gauge end and blow/force some water down to clear it.

 

[ExplorerTarga52]

Hi , I have a Brig with a 20hp Suzuki and bought a smart GPS speedo that doesn't need holes . KUS Waterproof Digital GPS Speedometer Odometer Gauge With Backlight For Vessel Boat Yacht 85mm 9-32V (White) They do an analogue version as well , I got mine off Amazon and works a treat

 

[PalmaTarga]

Try pulling the hose through first. You would probably have enough slack/extra length inside the boat to pull through and cut off a couple of foot or so to remove any blockage that may be there.

If not, maybe replace the Pitot tube, they get a bit brittle with age. Here is the first thing that came up on google in the US for reference. https://suzukioutboardmarine.com/product/suzuki-4-speedometer-pitot-tube/

You'll find them in most chandlers, Teleflex make one which is about a tenner.

 

[Jeepster]

I second what ExplorerTarga52 said...Ditch the old fashioned and inaccurate analogue speedo and go for a digital GPS one instead. The beauty of the latter is they are not only far more accurate but they work at low speeds too and most offer additional functions, not just a speedo. My one is a digital compass, mileometer, and trip counter too! They cost about £50 on ebay. Here is the one I have, with a white face (it is also available with a black face)...Make sure you get one with a backlight colour to suit your dash Mine has an orange backlight, but some come with a blue backlight.: https://www.ebay.co.uk/itm/1pc-85mm...968324?hash=item285f348144:g:b~YAAOSw59hbPcmH

 

[PalmaTarga]

Depending on where you do your boating and how far you travel. GPS speedo's work as Speed over Ground which is fine if there's no tide. If you're in the UK which has a strong tide and you're navigating some distances, you need Speed Through Water.

 

[Jeepster]

Depending on where you do your boating and how far you travel. GPS speedo's work as Speed over Ground which is fine if there's no tide. If you're in the UK which has a strong tide and you're navigating some distances, you need Speed Through Water.

But If I am sailing from point A to point B say, and I have a GPS chartplotter and speedo, so I know my location and the distance between the two points...to accurately calculate how long the journey will take me, I simply need to know my speed over the ground (or more accurately, over the water). Therefore the speed of the tide (or the speed of the boat through the water), or the wind, becomes irrelevant doesn't it? Or am I missing something?

 

[PalmaTarga]

Yes you will, but it will be useful knowing both, especially if you are passage planning in tidal water. Personally I like to know both even though my boating is all now non tidal. It will also give you a better understanding on how your engine is performing at revs vs speed. For example 20 knots at 3000rpm will read on the log while the GPS may read 15 knots due to the moving water under the boat.

Fixing your original will be relatively simple not to mention cheaper than replacing and you have the benefit of both.