Tachometer, inboard vs outboard

[Csprin1]

We have all but built our pontoon from scratch. We ordered a console, and he went to a boat yard to get to the gauges. The tachometer is spinning in circles when you turn it on. We checked the ground wire and cleaned it the best we could but it's still not working. It does go up to 6000 RPMs, and he said that he read that it needs to be 7000 for outboards.

We're trying to keep the gauge set relatively the same. And I'm having a hard time finding one that closely matches the set. They're Farias and they look like they have a brown backing, with stainless steel rings. I did find one that went up to 7000, the faria boat inboard tachometer gauge TC5006B3 3/8 inch silver and black. But now I'm confused because it goes up to 7,000.
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Everything has kind of been a learning curve for us, and we definitely learned a lot doing this. However, we are unsure what the difference is between an in board and outboard. Can somebody look at this and see if it is compatible with a 70 horsepower Johnson motor? If not, can you recommend one that looks close to this? I would like to avoid buying a whole new set, when it's only one that needs to be replaced.

https://www.greatlakesskipper.com/faria-boat-inboard-outboard-tachometer-tcc029a-larson-226-c029


​​​​​​​TIA

 

[Sea Rider]

Welcome to IBoats,

Need to know what's the max wot rpm range factory stated for your motor to buy whether a 6 or 7 K tach...

Happy Boating

 

[HotTommy]

There is a Johnson outboard specific forum here on iboats if you want to try there too.

 

[GA_Boater]

Csprin1 Moved this out of the Pontoon section to the JonnyRude section for you.

 

[sam am I]

The signal source I/B verse O/B will be most likely different and could be the issue here. i.e., The I/B tach might be designed to hook up to a 4 stroke distributor and have a setting switch(or be hardwired) for 4-6-8 cylinders as where the O.B. tach would be designed to hook up to a 2 stroke stator and have a setting switch(or be hardwired) for 8-10-12 poles. All of which, then of course, makes the pulse/rev that the tach expects to see and be cal'd to show.

The 7K (6K) max isn't really the deterministic factor here per-se, you'd just need to know the engine type as in my example above.

 

[Faztbullet]

You can download a form from the Faria site and send gauges in and have repaired...

 

[Csprin1]

The signal source I/B verse O/B will be most likely different and could be the issue here. i.e., The I/B tach might be designed to hook up to a 4 stroke distributor and have a setting switch(or be hardwired) for 4-6-8 cylinders as where the O.B. tach would be designed to hook up to a 2 stroke stator and have a setting switch(or be hardwired) for 8-10-12 poles. All of which, then of course, makes the pulse/rev that the tach expects to see and be cal'd to show.

The 7K (6K) max isn't really the deterministic factor here per-se, you'd just need to know the engine type as in my example above.

We have a 70hp Johnson motor. The original gauge works, but the set is broken. We took those back and changed it out. Now the needle goes up to about 40 and drops to 0.

 

[sam am I]

We have a 70hp Johnson motor.

Understood

The original gauge works, but the set is broken.

I'm lost......So the original tach worked? HOWEVER, you bought a new cluster of gauges ("a set") and "the set is broken"? Super lost now.......You mean the tach in the new cluster (the "broken set") doesn't work right either?

We took those back and changed it out. Now the needle goes up to about 40 and drops to 0.

So you bought another cluster of gauges and that tach doesn't work right as well? "goes to 40 and drop to 0"?

40 what? 40RPM? How in the world could you even disseminate 40RPM? Is it digital?


Again, the tach (included in ANY cluster [set] of gauges) has to be designed for a O/B motor, I'm not a JohnnyRude guy but I assume those tach's hook to a stator, e.g., 6/8/10/12 poles ..........

https://fariabeede.com/site_manuals/IS0086_V.pdf

https://forums.iboats.com/forum/boat...4696-tach-test