tiny tach

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cazzascotta

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Hello, I've just installed the tiny tach on my yanmar 2GM20F, and all seems to run. But when engine is in idle at the lowest rpm the tiny tach reports 1050 rpm, that I think is too high for this engine.
My question: how can I control if the engine has a too high rpm when in idle or if it is the tiny tach wrong?
 
I'm not sure that 1050 is too high, doesn't the handbook or workshop manual give you the range at tickover?

As it happens, 1050 rpm is exactly what my Bukh 24 (two cyl) diesel runs at on tickover, so within the range given in the manual. As suggested, if you are still concerned, borrow or hire a manual tachm'r and check the actual rpm of the engine directly.
 
[ QUOTE ]
Hello, I've just installed the tiny tach on my yanmar 2GM20F, and all seems to run. But when engine is in idle at the lowest rpm the tiny tach reports 1050 rpm, that I think is too high for this engine.
My question: how can I control if the engine has a too high rpm when in idle or if it is the tiny tach wrong?

[/ QUOTE ]

You should be able to adjust the tickover where the throtle cable meets the engine, have a play and see if the revs do drop to the point where the engine is not idling nicely and see what the Tiny Tach reports?
 
According to the Owners manual the idle speed should be 850rpm ±25.

The manual also includes instructions for checking the remote control cable which might be worth a look if you feel that the revs are too high.

Checking the actual rpm with a mechanical tacho or a revolution counter and stopwatch is a sensible idea if you can obtain the equipment. It's the sort of thing everyone has isn't it? I know I have inherited two mechanical tachos and I am sure there s a rev counter somewhere as well!
 
1050rpm is fine. I've just increased the tickover on my 2GM20 to this level to cope with engaging reverse on a Kiwi prop. Less vibration too.
 
Yes, it might solve the Kiwi problem, but puts a big load on the gearbox if you engage gear at 200 rpm higher than the recommended no load speed.
 
[ QUOTE ]
Yes, it might solve the Kiwi problem, but puts a big load on the gearbox if you engage gear at 200 rpm higher than the recommended no load speed.

[/ QUOTE ]And where do you get this mis-information from?
The engine manufacturer does not know which g'box will be fitted nor the application. The G'box manufacturer sets the engage/disengage speeds for their gearboxes, not the engine manufacturer.
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Artificial Intelligence is no match for Natural Stupidity
 
Why, pray is this misinformation? The Yanmar is fitted with a Yanmar gearbox at the factory and the engine comes with the tick over speed as in the manual page 4.5

The reason for upping the tickover speed with a Kiwi prop is because on some (relatively) low hp engines there is insufficient power when reverse is engaged at the factory set no load speed to turn the blades around and provide reverse thrust - all covered in the Kiwi website.

Just suggesting that it may not be kind on the gearbox.
 
Just to re-inforce the lower tickover speed, page 10.60 has instructions for setting up the cables and suggests setting "the idling engine speed at between 750 and 800 rpm" inconsistent with the previous speed which was to do with setting the governor, but a long way below 1050.

Perhaps a "real" Yanmar expert rather than this careful but amateur reader of manuals will care to comment.
 
Do these "tiny tach" things actually work well? I have had a look at the website and it looks really good. Might buy one of the diesel models myself (Yanmar 3GM30).
 
I have just installed one, it was quite straightforward, make sure you have the correct size for your injector pipes. I stated engine model and they sent the right one. Only difficulty was that the wires for 12V + and - were very fine, not easy to make good connections.

Seems to work well, giving engine speed when engine on, and hours-minutes run when off.

I have not used the boat much since installation, only slight surprise was that I thought rpm was lower than expected for the throttle opening. Getting perfectly acceptable boat speed though.

Will do some more checks next time out.
 
checked my tyny tac with a RS electronic Infra red Gismo.12RPM difference.nuff said.

Yanmars tick over at 825-870 .My new shiny ym 15 has a spring loaded connection from cable to the fuel pump lever but no instructions which way round to fit it. Can any body help ,does spring go behind or in front of lever( front is cable side)
 
No, but Tiny Tach will, ask them, I just said my engine was a Volvo MD7 when I ordered and they sent the right transducer fitting.
 
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