Wema Tachourmeter combines a 0-4k or 0-8k tachometer with an LCD hour meter.
Please note: The 3k tachometer is special order only (available with MOQ of 25). Two versions are stock items; the 4k & 8k. Please contact us for further information.
1) Wema tachometers need to be calibrated before use. They should be installed by a qualified marine electrician.
2) Customer installation is possible if engine specifications are known.
3) If specifications are unknown then it is often possible to connect the tachometer to the W-terminal on the alternator and cycle through settings until the known idling RPM is displayed on the gauge. The throttle can then be depressed to check that the full range of movement is displayed on the gauge.
PROFESSIONAL INSTALLATION GUIDELINES:
Q – The number of the magnet poles (outboard engine), or number of the cylinders (inboard engine); Max – The maximum speed the gauge can read; R – The speed ratio to be set;
FORMULA: R = (Q/2 )* (Max/6000)
For example: For a 3 cylinder, 4 stroke engine where the full scale of the tachometer is 4000RMP;
R=(3/2)*(4000/6000)=1.0; Adjust the speed ratio on the tachometer to 1.0.
If it is a two stroke engine, speed ratio = 3*(RPM/6000); For example, if it is a 4000RPM Tacho, speed ratio = 3*(4000/6000)=2;
Based on the calculated results, enter the settings mode and adjust it to the corresponding speed ratio.
SPEED RATIO ADJUSTMENT:
a. Hold down the rubber button on the back of the gauge for 3 seconds; it will then enter 'settings mode'. If the button is held for more than 3 seconds, it will exit settings mode.
b. As the button is pressed, the value will increase. To decrease the value; release the button and press again. The value will now decrease. The longer you press the button, the faster the value will change. [The minimum step value is 0.5 and the adjustable range is 0.5 - 250]
c. When you get to the required speed ratio value release the button. The tachometer will save the selection after 3 seconds.
To re-adjust the value, repeat steps a-c.
[If the deviation is big, the speed ratio can be a bit bigger than calculated value; If the deviation is small, the speed ratio can be a bit smaller than calculated value.
The gauge needle points at the corresponding positions when adjusting the speed ratio.]
If above calculation description is not clear to you, you can adjust it according to the idle speed of the engine. The engine remains at idle state after it is started; enter the settings mode and adjust the speed ratio until the gauge needle is close to the idle state.
Here you can find answers to some popular questions, for anything else please contact us by email or by phone and we'll be happy to help.